Interbody fusion material retention methods

ABSTRACT

Methods of inserting and retaining interbody fusion material are disclosed. In some embodiments, the methods include inserting an anchored implant comprising a bone anchoring portion and an engagement portion. A method may also include inserting at least one bone fusion material within a disc space between two adjacent vertebral bodies. In some embodiments, a method includes driving the bone anchoring portion into an outer surface of at least one of the adjacent vertebral bodies and recessing the bone anchoring portion within the outer surface of the at least one adjacent vertebral body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/690,041, filed Jan. 19, 2010, which is acontinuation of U.S. patent application Ser. No. 12/617,613, filed Nov.12, 2009, now U.S. Pat. No. 8,323,341, which is a continuation-in partapplication of U.S. patent application Ser. No. 12/524,334, having a 371(c) date of Mar. 10, 2011, which is a National Phase Application ofInternational Application No. PCT/US2008/075496, filed Sep. 5, 2008,published as International Publication No. WO 2009/033100 on Mar. 12,2009, which claims the benefit of U.S. Provisional Application Nos.60/967,782, filed Sep. 7, 2007; 61/066,334, filed Feb. 20, 2008;61/066,700, filed Feb. 22, 2008; and 61/126,548, filed May 5, 2008. U.S.patent application Ser. No. 12/617,613 claims the benefit of U.S.Provisional Application No. 61/198,988, filed Nov. 12, 2008. Thisapplication hereby expressly incorporates by reference each of theabove-identified applications in their entirety.

FIELD OF THE INVENTION

The invention relates generally to tissue anchors, delivery methods, andassociated treatments. Anchors according to one or more embodiments canprovide superior pull-out resistance, stability and may, in someembodiments, increase contact with tissue involving a reduced amount ofpenetration. Delivery methods include linear, lateral, and off-angleimplantation or driving of anchors along, against or within tissuesurfaces.

DESCRIPTION OF THE RELATED ART

Anchors described herein can be used throughout the human body and havegeneral applicability to fastener art. Such anchors can be used to joinor anchor like or disparate materials or tissues together, maintainalignment of materials, reinforce a fracture within a material, andprovide an attachment site along or within a materials surface.Generally the art includes both staples and screws. For example, U.S.Pat. No. 7,131,973 to Hoffman discloses an anchor and delivery systemfor treating urinary incontinence. The distal portion of the deliverytool is curved and hooked such that pulling on the instruments handleeffects a retrograde delivery of the anchor. U.S. Pat. No. 5,366,479 toMcGarry et al. discloses a staple and delivery system. The staple isflat but contains a pair of inwardly curving prongs. U.S. Pat. No.5,391,170 to McGuire et al. discloses an angled screw driver forinserting bone screws in ligament tunnels as part of a ligamentreconstruction procedure. U.S. Pat. No. 5,217,462 to Asnis et al.discloses a screw and driver combination having threaded shank andsleeve that cooperate to hold and release the screw. U.S. Pat. No.5,002,550 to Li discloses a suture anchor with barbs and an installationtool that includes a curved needle for attaching a suture.

SUMMARY

Systems, devices, and methods are provided for graft containment and/orgraft impaction. Systems, devices, and methods are also provided forsoft tissue containment and/or impaction. In certain embodiments, thesystems, devices, and methods can be utilized to facilitate surgicalvertebral fusion procedures, disc reconstruction, disc augmentation,and/or disc repair.

In one embodiment, a fusion system for graft containment and/or graftimpaction comprises an anchored implant, graft material, a fusion cage,and/or one or more implantation or delivery tools. In anotherembodiment, the fusion system for graft containment and/or graftimpaction comprises an anchor and an engagement member. In yet anotherembodiment, the fusion system for graft containment and/or graftimpaction comprises an anchored implant and graft material. In stillanother embodiment, the fusion system comprises an anchor.

In another embodiment, a method of providing an anchor along a vertebralbody endplate is provided. The vertebral body comprises an endplatesurface and a lateral peripheral surface that extends around thevertebral body and is substantially perpendicular to the endplatesurface. In one embodiment, the method comprises providing an anchorhaving a vertical planar member having a leading edge, a trailing edge,and a tapered cross-section and a lower planar member having a leadingedge and a trailing edge, wherein the lower planar member forms an anglewith and is offset to the vertical planar member. The offset angle canbe from 10 to 180 degrees. The anchor can also include an engagement orconnection member connected to the vertical planar member. The methodfurther comprises driving the anchor into an outer surface of avertebral body such that a least a portion (e.g., the engagement orconnection member) of the vertical planar member remains proud or isflush with an endplate surface of the vertebral body. The method alsocomprises establishing the vertical planar member of the anchor throughand within the lateral peripheral surface of the vertebral body suchthat a trailing edge of the vertical planar member extends into thelateral peripheral surface of the vertebral body and establishing thelower planar member entirely below the endplate surface and/or withinthe lateral peripheral surface of the vertebral body such that theanchor is configured with two offset planes beneath the endplate surfaceof the vertebral body without expansion (e.g., “mushrooming” ordeployment of barbs) of said anchor. In one embodiment, the taperedcross-section of the vertical planar member tapers from a widercross-section at an intersection with the lower planar member to anarrower cross-section as the vertical planar member extends away fromthe lower planar member. In another embodiment, the two offset planescan both be recessed within, or driven at least flush with, the lateralperipheral surface of the vertebral body.

In another embodiment, bone anchors are adapted to resist backout ormigration under eccentric or off-axis loading of the anchor. Resistanceto backout or migration from the applied moment is provided by a portionof the anchor embedded within a vertebral body and the transmission offorces against tissue adjacent the embedded portion of the anchor. Inone embodiment, a recessable bone anchor that is resistant to extrusionis provided. The recessable bone anchor comprises a horizontal memberhaving a proximal end, a distal end, an upper surface and a lowersurface and a lateral extension extending from the horizontal memberproximate to the distal end of the horizontal member. In one embodiment,the lateral extension comprises a leading edge facing the proximal endof the horizontal member and terminating at an implant attachment site.In one embodiment, the horizontal member comprises non-uniform surfaces.The upper surface between the lateral extension and the distal end ofthe horizontal member is treated and/or modified to present a surfaceconfigured or optimized for bone fixation or traction and the lowersurface between the lateral extension and the proximal end is treatedand/or modified to present a surface configured or optimized for bonefixation or traction. The remaining portions of the upper and lowersurfaces are adapted to present a smooth or non-modified or non-treatedsurface.

In one embodiment, the lateral extension of the bone anchor extendsvertically or substantially vertically from the horizontal member anddefines a plate-like keel operable to resist torsional loads on theimplant attachment site. The lateral extension is wedge-shaped anddecreases in width as it extends away from the horizontal member,thereby resisting vertical pull-out and embedding itself as it is driveninto bone without an expansion effect. In one embodiment, the boneanchor can be dimensioned such that it can be press-fit or implantedinto bone without first forming a pilot hole or performing similar sitepreparatory measures.

In another embodiment, bone anchors are adapted to resist backout ormigration under multi-directional, eccentric or off-axis loads.Resistance to backout or migration is provided by multiple, connectedsurfaces of the embedded portion of the bone anchor that are arranged indifferent planes.

In one embodiment, a method of impaction grafting to facilitateinterbody fusion between adjacent vertebral bodies is provided. Themethod comprises providing an anchored implant having a bone anchoringmember and a graft engagement member and providing bone graft material.The method further comprises accessing an intervertebral disc spacebetween adjacent or opposing vertebral bodies and inserting the bonegraft material within the disc space. The method also comprises drivingthe bone anchoring member into an outer surface of one of the adjacentvertebral bodies. The method further comprises engaging the insertedbone graft material and displacing the inserted bone graft materialfurther into the disc space with the graft engagement member. The methodalso includes recessing the bone anchoring member within one of theadjacent vertebral bodies. In one embodiment, the bone anchoring memberis recessed such that no portion of the anchoring member extends beyondor proud of an outer surface of the vertebral body within which it isimplanted. In one embodiment, the bone anchoring member is recessed suchthat a trailing edge of the bone anchoring member is at least half acentimeter within said outer surface of said vertebral body.

In another embodiment, a method of impaction grafting and repairing softtissue within an intervertebral disc is provided. In one embodiment, themethod comprises identifying a weakened portion of an anulus fibrosus ofan intervertebral disc and accessing the weakened portion of the anulusfibrosus. The method further comprises providing an anchored implanthaving a bone anchoring member and an engagement member. The method alsocomprises driving the bone anchoring member into an outer surface of avertebral body adjacent the weakened portion of the anulus fibrosus. Themethod also comprises impacting soft tissue extruding from the weakenedportion of the anulus fibrosus and displacing the soft tissue furtherinto the disc space with the engagement member. The method furthercomprises recessing and establishing the bone anchoring member withinthe outer surface of the vertebral body. In one embodiment, the methodalso comprises containing the soft tissue and preventing migration orherniation of the soft tissue. The graft containment method can be usedto facilitate vertebral fusion, anular reconstruction, discaugmentation, and/or disc repair.

In one embodiment, the method of impaction grafting and repairing softtissue within an intervertebral disc further comprises identifying aweakened intervertebral disc. In another embodiment, the methodcomprises augmenting a diseased vertebral endplate surface caused bysaid accessing the disc space, for example, by inserting augmentationmaterial within the intervertebral disc and positioning the augmentationmaterial to contact an inner surface of the anulus fibrosus adjacent aweakened portion. In alternative embodiments, the weakened portioncomprises a defect, herniated portion, or naturally-occurring hole inthe anulus fibrosus. In one embodiment, the soft tissue comprises nativenucleus pulposus material. In another embodiment, the soft tissuecomprises prosthetic, artificial, or augmentation material.

In another embodiment, the methods of impaction grafting to facilitatefusion also comprise inserting a fusion cage within the disc space. Inone embodiment, the methods further comprise impacting the inserted bonegraft material against the inserted fusion cage. In one embodiment,continuous force is applied to the inserted bone graft material. Inalternative embodiments, the bone graft material comprises autograft,allograft, xenograft, or synthetic material. The bone graft material canbe loose graft material or a dense bone graft. The disc space can beaccessed using any one or a combination of the following surgicalapproaches: a posterior lumbar interfusion (PLIF) approach, atransforaminal lumbar interfusion (TLIF) approach, an anterior lumbarinterfusion (ALIF) approach, and an extreme lateral interfusion (XLIF)approach. The methods of impaction grafting to facilitate fusion can beused to fuse adjacent lumbar, thoracic, or cervical vertebrae.

In one embodiment, the methods of graft impaction, soft tissueimpaction, and/or graft containment further comprise removing at least ade minimis portion of an intervertebral disc within the disc space. Inanother embodiment, no portion of the intervertebral disc is removed.Removing at least a de minimis portion of the intervertebral discincludes removing a portion of the anulus fibrosus or the nucleuspulposus, or a portion of both.

In one embodiment, the methods of graft impaction, soft tissueimpaction, and/or graft containment further comprise penetrating ananulus fibrosus of the intervertebral disc and forming a hole throughthe anulus fibrosus. In another embodiment, the methods also comprisedriving the bone anchoring member into the outer surface of thevertebral body at an angle substantially parallel to the endplate of thevertebral body. In still another embodiment, the methods also comprisedriving the bone anchoring member to a position wherein at least aportion of the bone anchoring member resides at least partially withinor is in contact with the anulus fibrosus. In yet another embodiment,the methods further comprise recessing the bone anchoring member suchthat a trailing end of the bone anchoring member is recessed greaterthan 1 mm within the outer surface of the vertebral body within which itis implanted. In another embodiment, the bone anchoring member can beimplanted such that a trailing end of the bone anchoring member is atleast flush with the outer surface of the vertebral body.

In another embodiment, a method of graft containment is provided. Themethod of graft containment provided herein is used to facilitatevertebral fusion procedures. The method of graft containment can befacilitated with a recessable anchored implant having an anchor memberand an engagement or containment member. In one embodiment, the methodof graft containment comprises creating an access hole within anintervertebral disc, accessing and preparing the space within the discand opposing endplates, selecting a volume of graft material, andimplanting the graft material within the disc space. The method furthercomprises selecting an engagement member operable to block the accesshole, inserting the engagement member at least partially beyond theouter aspect of the access hole such that no portion of the engagementmember extends beyond the lateral outer surfaces of the adjacentvertebral bodies, implanting an anchor within one of the adjacentvertebral bodies such that no portion of the anchor is proud or extendsbeyond (e.g., is recessed, countersunk, or flush) the lateral outersurface the vertebral body within which it is implanted; and connectingthe engagement member to the anchor member. In certain embodiments, themethod of graft containment is performed without expansion of the anchormember. For example, no portion of the anchor member extends outside ofthe boundaries of the void in the bone created by entry into thevertebral body.

In another embodiment, a method of impaction grafting, graftcontainment, and/or disc repair or augmentation comprises identifying afirst vertebral body and a second vertebral body, wherein the firstvertebral body comprises a first outer surface and a first endplate andidentifying a disc space bordered by the first vertebral body and thesecond vertebral body. The method further comprises providing a bonegraft containment system comprising a bone graft, a support member forcontaining the bone graft and a bone anchor. The bone anchor isconfigured for insertion into the first outer surface and for presentingan attachment site along the first endplate. The first outer surface isoffset at an angle substantially perpendicular from the first endplate.The support member is coupled to the bone anchor.

The bone anchor comprises a neck having a length defined by a sharpenedleading edge and a trailing end and an attachment site along at least aportion of its length. The attachment site is attachable to the supportmember and is configured to extend above the first endplate. The neckfurther comprises a bottom portion terminating in two or more keels,which are configured for pull-out resistance and stability by presentinga larger surface area below the first endplate and embedded in the firstouter surface. The keels form an angle of about 10 to about 180 degreesrelative to each other and each of the keels comprises sharpened leadingedges. In one embodiment, the neck is perpendicular to the keels to forma “T” shape. The attachment site is configured to be offset relative toboth the anchor's angle of insertion and the neck to present theattachment site along the first endplate, while the keels are insertedinto the first outer surface.

The method further comprises inserting the bone graft into the discspace. The method also comprises driving the sharpened leading edges ofthe keels into the first outer surface while simultaneously advancingthe support member along and across the first endplate until said anchoris countersunk within the outer surface. The method further comprisespositioning the support member to contain the bone graft, therebyreconstructing or augmenting the endplate of the first vertebral body tominimize extrusion of the bone graft from the disc space.

In one embodiment, a method of impacting graft during vertebral fusionis provided. The method comprises implanting a cage across anintervertebral disc space and implanting loose bone graft materialwithin the disc space. The method also comprises partially implanting agraft containment and/or impaction device and impacting the loose bonegraft material against the cage. The method further comprises fullyimplanting the graft containment and/or impaction device below or flushwith an outer surface of an adjacent vertebral body to prevent migrationof the loose bone graft material and the cage. In another embodiment,the method comprises inserting the loose bone graft material beforeinserting the bone cage.

Although one anchor is provided in some embodiments, two, three, four,five, ten or more anchors are used in alternative embodiments. Theanchor delivery tools and instruments described below may be used todeliver any of the anchors described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-B show an axial and sagittal view respectively of a spinesegment and various anchor sites.

FIG. 2 shows an exploded view of one embodiment of a curvilinear anchorand delivery instrument.

FIG. 3 shows a perspective view of one embodiment of a curved twopronged staple type anchor.

FIGS. 4A-E show a sequence involving loading an anchor into a deliveryinstrument and forcing it out of the lateral opening at the distal endof the delivery instrument according to one embodiment.

FIG. 5 shows an exploded view of one embodiment of a delivery instrumentand detachable sleeve.

FIGS. 6A-G show a delivery sequence involving a vertebral endplateaccording to one embodiment.

FIG. 7 shows a prior art bone screw and intervertebral anatomy.

FIG. 8 shows an embodiment of an anchor according to one or moreembodiments.

FIG. 9 shows another embodiment of an anchor according to one or moreembodiments.

FIG. 10 shows another embodiment of an anchor according to one or moreembodiments.

FIG. 11 shows one embodiment a delivery tool.

FIG. 12 shows the delivery tool in the previous figure with an anchormounted

FIG. 13 shows an axial cross sectional view of a vertebral body andimplanted anchor.

FIGS. 14A-B show an expanded view and a frontal view of the implantedanchor in the previous figure.

FIG. 15 shows a sagittal view of the implanted anchor in the previousfigures.

FIG. 16 shows an axial cross sectional view of a vertebral body and adelivery tool inserted along an endplate in the vicinity of an anulusdefect or anulotomy.

FIG. 17 shows an axial cross sectional view of a vertebral body whereinan anulus reinforcement device has been implanted along and within theanulus and is attached to an anchor embedded within the vertebral body.

FIGS. 18A-C show various views and features of anchors according to oneor more embodiments.

FIG. 19 shows various profiles of the keel portion of one or moreanchors.

FIG. 20 shows a perspective view of another embodiment of an anchoraccording to one or more embodiments with a plate-like attachment meanssuitable for three sutures.

FIG. 21 shows a perspective view of another embodiment of an anchoraccording to one or more embodiments with an “eye” attachment means.

FIGS. 22A-B show embodiments of the anchor and delivery tool. FIG. 22Ashows a perspective view of another embodiment of an anchor according toone or more embodiments having a three legged keel portion and designedsuch that only the attachment portion remains proud on the tissuesurface. FIG. 22B shows a delivery tool for driving an anchor with amated surface and alignment pins.

FIGS. 23A-B show a perspective view of another embodiment of an anchoraccording to one or more embodiments having a flexible linkage member.

FIGS. 24A-C show a series of perspective views of one embodiment of ananchor and barrier system according to one or more embodiments.

FIGS. 25A-C show a series of perspective views of another embodiment ofan anchor and barrier system according to one or more embodiments.

FIGS. 26A-B show a side view and perspective view of an anchor with asharpened leading edge having a recessed region corresponding to thecupped cortical rim of a vertebral endplate.

FIG. 27A illustrates an embodiment of a stabilization assembly incombination with a separate anchor.

FIG. 27B illustrates an embodiment of an anchor secured to bone tissueand connected to an implant.

FIGS. 28A-28F illustrate various approaches of an implantation tool totarget tissue.

FIGS. 29A-29F illustrate a plurality of lateral views of variousembodiments of anchors and attachment positions and locations withrespect to patient tissue.

FIG. 30A illustrates a top view of one embodiment of a support member.

FIGS. 30B and 30 C illustrate first and second configurations of anembodiment of a support member connected to an anchor.

FIG. 31A illustrates an embodiment of an anchor partially engaged with asupport member.

FIG. 31B illustrates the embodiment of anchor and support member of FIG.31A in a fully engaged configuration.

FIG. 31C illustrates a top view of an embodiment of a support member inan insertion configuration as maintained by a sleeve.

FIG. 31D illustrates a support configuration of the support member ofFIG. 31C.

FIG. 32 illustrates an embodiment including a plurality of anchorsconnected to respective gate numbers.

FIG. 33 illustrates an embodiment of anchors and attached gate membersin one embodiment of an implanted position.

FIGS. 34A-34C illustrate a plurality of embodiments of anchors andattached gate members and corresponding implantation locations.

FIGS. 35A and 35B illustrate two embodiments of anchors and attachedgate members and corresponding implantation configurations.

FIGS. 36A-36C illustrate embodiments of an anchor and attached gatemember and respective fixation locations with respect to an inner andouter surface of an anulus fibrosus.

FIG. 37 illustrates an embodiment of an anchor and attached gate memberhaving a plurality of interweaved fingers.

FIGS. 38A and 38B illustrate top and side schematic views respectivelyof various shapes and configurations of gate members.

FIG. 39A illustrates an embodiment of multiple anchors and attachedrespective gate members where the gate members are interweaved but notaligned with each other.

FIG. 39B illustrates an embodiment of multiple anchors and connectedrespective gate members wherein the gate members associated with arespective anchor are substantially aligned with each other.

FIG. 39C illustrates schematic top views of various configurations ofgate members including concave, multifaceted, and rounded.

FIG. 40A illustrates an embodiment of anchors and attached gate members,wherein opposing gate members are substantially mirror images of eachother and positioned in substantial alignment.

FIG. 40B illustrates an embodiment of anchors and attached gate members,wherein opposing gate members engage such that one gate member at leastpartially nests within the opposite gate member.

FIG. 41 illustrates an embodiment of anchors and attached gate memberswherein opposed gate members are connected by an embodiment of aconnector.

FIGS. 42A and 42B illustrate side and end views respectively ofembodiments of first and second anchor structures.

FIGS. 43A-43D illustrate one embodiment of an implantation sequence ofthe embodiments of first and second anchor structures of FIGS. 42A and42B.

FIGS. 44A and 44B illustrates a side view of another embodiment of firstand second anchor structures.

FIGS. 45A-45C illustrate one embodiment of an implantation sequence ofthe embodiment of first and second anchor structures of FIG. 44.

FIGS. 46A and 46B illustrate perspective and side views respectively ofan embodiment of a support implant.

FIGS. 47A and 47B illustrate an anterior posterior view and lateral viewrespectively of an embodiment of a support implant provided with aplurality of markers configured to indicate a configuration of thesupport implant at an implantation location.

FIG. 48 and Detail A are a schematic side view of an embodiment of asupport implant including an anchor and a moveable support structureattached thereto.

FIG. 49 illustrates an embodiment of a delivery tool configured tofacilitate the implantation of embodiments of support implants.

FIGS. 50A-50E illustrate one embodiment of an implantation sequenceutilizing embodiments of the delivery tool of FIG. 49.

FIG. 51 illustrates an embodiment of delivery tool and attached supportimplant defining a plurality of adjacent locating surfaces configuredfor support and alignment with patient tissue.

FIGS. 52A and 52B illustrate embodiments of delivery of an anchor orsupport implant utilizing embodiments of the delivery tool of FIG. 49.

FIGS. 52C-52F illustrate a plurality of configurations of a supportimplant deployed at various implantation locations.

FIGS. 53A-53C illustrate an embodiment of an implantation process andcooperating anchor and delivery tool.

FIGS. 54A-54C illustrate another embodiment of a delivery tool andembodiments of operation of the tool at various stages of animplantation procedure.

FIGS. 55A and 55B illustrate embodiments of an implantable supportanchor in an implanted side view and perspective view respectively.

FIGS. 56A and 56B illustrate embodiments of an implantable supportanchor in side view and end view respectively.

FIGS. 56C and 56D illustrate the embodiments of an implantable supportanchor of FIGS. 55A and 55B and an embodiment of driver adapted for usetherewith.

FIGS. 57A and 57B illustrate perspective views of embodiments ofimplantable support anchor with a support structure and multiple keelmembers.

FIGS. 57C and 57D illustrate schematic side views of the embodimentsillustrated by FIGS. 57A and 57B in an implanted position.

FIGS. 58A and 58B illustrate perspective views of further embodiments ofimplantable support anchors.

FIGS. 59A and 59B illustrate side views of embodiments of implantablesupport anchor having a movable arm.

FIG. 59C illustrates a schematic side view of the embodimentsillustrated by FIGS. 59A and 59B in an implanted position.

FIG. 59D is a top view of the embodiments illustrated by FIGS. 59A and59B.

FIGS. 60A and 60B illustrate schematic front and side views,respectively, of an embodiment of an implant for impaction of graft orsoft tissue.

FIGS. 60C and 60D illustrate perspective views of the implantillustrated in FIGS. 60A and 60B.

FIGS. 61A-61F illustrate an embodiment of an example transforaminallumbar interbody fusion (TLIF) procedure facilitated by use of theimplant of FIGS. 60A-60D for impaction grafting.

FIG. 62 illustrates a perspective view of the final implantation step ofthe fusion procedure of FIGS. 61A-61F.

FIG. 63 illustrates an embodiment of the implant of FIGS. 60A-60D in animplanted position using a TLIF procedure.

FIG. 64A illustrates an embodiment of the implant of FIGS. 60A-60D in animplanted position using a posterior lumbar interbody fusion (PLIF)procedure.

FIG. 64B illustrates an embodiment of two graft impaction implantsimplanted using a PLIF procedure.

FIG. 65A illustrates an embodiment of two graft impaction implantsimplanted in conjunction with an anterior lumbar interbody fusion (ALIF)procedure.

FIG. 65B illustrates an embodiment of a graft impaction and/orcontainment method and device for use in conjunction with a surgicalfusion procedure.

DETAILED DESCRIPTION

Several embodiments relate generally to tissue anchors and methods ofdelivering tissue anchors to the intervertebral disc or other siteswithin the body. In some embodiments, the tissue anchors provideincreased pull-out resistance, improved stability and/or increasedcontact with tissue involving a reduced amount of penetration. In someembodiments, delivery methods are minimally invasive and include, butare not limited to, linear, lateral, and off-angle implantation ordriving of anchors along, against or within tissue surfaces. In severalpreferred embodiments, bone anchors are provided.

The term “anchor” as used herein shall be given its ordinary meaning andshall also include, but not be limited to, nails, staples, screws,fasteners, sutures, spikes, tacks, keys, pegs, rivets, spikes, bolts,and pins. In several embodiments, the anchor comprises one or more tinesor prongs. In one embodiment, the anchor is forked. In some embodiments,the anchor may be straight, curved, or partially curved.

In several embodiments, the anchors disclosed herein are particularlysuited for hard tissues such as bone. In other embodiments, soft tissueanchors are provided. One or more embodiments of the anchor can bedelivered into a tissue and be secured within said tissue and resistextraction, migration, and/or rotation. Such stability is especiallyimportant in environments like the spine, where the anchor is adjacentdelicate nerve tissue such as the spinal cord. However, in severalembodiments, the anchoring system may be used in other delicatevasculature such as the aorta.

Although several examples of sites appropriate for anchors are describedherein for use in the boney tissue of the spine and particularly thevertebral endplates, anchors according to the embodiments describedherein have broad applications. For example, the anchors describedherein may be used in the radial head, ulnar head, humeral head, tibialplateau, scapula, acromion, talus, malleolus, tendons and ligaments suchas the talo-fibular ligament, anterior cruciate ligament, patella tibialtendon, Achilles tendon, rotator cuff, and other tissues such as themeniscus. Further, anchors according to one or more embodiments can bedisposed within artificial tissues and/or prosthetics.

FIG. 1A provides a sagittal view of a spine segment. Also shown arenumerous potential anchor sites and are marked as “X.” FIG. 1B is anaxial view of the same spine segment and shows other possible anchoringsites including along or within a vertebral body, endplate, transverseprocess, spinous process, facet, and pedicle. In other embodiments, ananchor can be placed along the cortical rim of the endplate or mediallywithin the cancellous bone or relative to or within a pedicle, skull, orsacrum. Other anchoring sites include, but are not limited to: relativeto a defect within the disc either in the area of the defect, at theinterface of the anulus and nucleus or in the area of the nucleus.

In several embodiments, one or more anchors are used in connection withan anulus or nucleus augmentative device, as described in U.S. Pat. Nos.6,425,919; 6,482,235; 6,508,839; and 6,821,276, all herein incorporatedby reference. In one embodiment, one or more anchors are used to anchoran anulus augmentation device that is placed within or beyond a defectin the anulus to the vertebral endplates.

One or more embodiments comprise anchors or gates disclosed herein aremade at least partially of one or more of the following materials: anybiocompatible material, material of synthetic or natural origin, andmaterial of a resorbable or non-resorbable nature. The anchor may alsobe partially or wholly constructed from material including, but notlimited to, autograft, allograft or xenograft; tissue materialsincluding soft tissues, connective tissues, demineralized bone matrixand combinations thereof; resorbable materials including polylactide,polyglycolide, tyrosine derived polycarbonate, polyanhydride,polyorthoester, polyphosphazene, calcium phosphate, hydroxyapatite,bioactive glass, collagen, albumin, fibrinogen and combinations thereof;and non-resorbable materials including polyethylene, polyester,polyvinyl alcohol, polyacrylonitrile, polyamide, polytetrafluorethylene,polyparaphenylene terephthalamide, cellulose, and combinations thereof.Further examples of non-resorbable materials include carbon-reinforcedpolymer composites, shape memory alloys, titanium, titanium alloys,cobalt chrome alloys, stainless steel, and combinations thereof. In someembodiments, the anchor comprises titanium alloys or cobalt chrome.

In several embodiments, the anchor comprises an anchor body and ananchor attachment site. In one embodiment, the anchor attachment site isadapted to accept or connect to a suture, linkage element, threadedscrew, and/or provides a surface for ingrowth into an adjacentstructure. The anchor attachment site can be integral to the anchor or aseparate structure comprised of the same or different material as theanchor body. The anchor attachment site can be coupled to the anchorbody. For example, the anchor attachment site can be flexibly, rigidly,or rotationally connected to the anchor body.

The anchor attachment site can comprise one or more of the followingstructures: head, flange, plate, disc, protrusion, channel, hole, cleator eye. These structures can be placed at various positions along theanchor. For example, one or more of these structures may be placed at ornear the ends of the anchor, in the middle of the anchor, or at anyother desired position. In some embodiments, the anchor attachment sitecomprises mesh, fabric, or membrane material, or a combination thereof.The site may be parallel, perpendicular or angled with respect to thebody of the anchor. In one embodiment, the anchor attachment site islocated on an end or terminus of the anchor body.

In one embodiment, the anchor comprises one anchor body and one anchorattachment site. In another body, the anchor comprises one or moreanchor bodies and one or more anchor attachment sites. In oneembodiment, the anchor comprises one body and two attachment sites.

In one embodiment, at least a portion of the anchor or gate comprises abiologically active or therapeutic agent. For example, in someembodiments, at least a portion of the anchor can comprise growthfactors such as bone morphogenic proteins, insulin-like growth factor 1,platelet derived growth factor, and fibroblast growth factor. In oneembodiment, both the anchor body and anchor attachment portion of theanchor can be adapted to deliver a biologically active or therapeuticagent. In other embodiments, at least a portion of the anchor is coatedwith a biologically active or therapeutic agent.

Curvilinear Anchor

Anchors (including staples, nails, and other fastening or joiningdevices) according to one or more embodiments can be partially or whollyarcuate or curvilinear. The radius of curvature (the tightness orgentleness of the curve) can vary among embodiments as can the sectionof a circle corresponding to the anchor. For example, an anchor having a90 degree curve would appear as ¼ of a circle. Other ranges of curvesbetween 0-180 degrees are also possible. In some embodiments, forexample, the curvature is about 15, 30, 45, 60, 75, 90, 120, 150, or 180degrees.

An anchor can also be at least partially curved with a linear portionextending upward. In this embodiment the curved portion is adapted fordriving into a tissue and the straight portion remains proud, or abovethe surface. Depending upon how the anchor is driven into the surface,the proud portion of the anchor can be anywhere from 0-180 degreesrelative to the surface. The curvature of an embodiment of the anchorcan also be variable along the anchor. Such a variable curvature couldbe employed to increase or decrease pressure on tissues adjacent to theanchor. In one embodiment, the proud portion is about 15, 30, 45, 60,75, 90, 120, 150, or 180 degrees relative to the surface.

The surface or body of the anchor can be roughened, porous, barbed,lubricated, coated or impregnated with a biologically active ortherapeutic agent. The anchor can be in the form of a curved nail orstaple with a crown or bridge and having two or more prongs or legsextending therefrom. A slot or gap between the prongs in one ore moreembodiments of a staple can be aimed at a suture or other structurealready implanted in or along a surface and then hammered in placethereby anchoring the suture in place. The tips of the prongs of astaple can be beveled to effect a wedging action. By beveling or anglingthe inner, outer, front, and/or back of a prong tip, the prong will tendto travel in a particular direction. Moreover, the beveled tips cancomplement each other, work in opposition, or some combination thereof.In one embodiment the prong tips are beveled on the outside edge, inanother embodiment the tips are beveled on the inside edge. In yetanother embodiment, the top of one prong is beveled and the bottom ofanother is beveled. In addition, the cross section of prongs may bevariable along the length of the anchor. In one embodiment, the anchorprong's smallest cross section is at or near the tip and at its greatestfurthest from the tip, creating a wedge along the curve of the anchor.This may aid in increasing compression on all or part of the bone orother tissue in contact with the anchor.

In another embodiment, an anchor can be resiliently flexible such thatafter passing through a curved slot or deflecting surface of thedelivery device, the anchor (including staples, nails, etc) straightensout to its original shape as it is advanced out of the device and intothe tissue. The original shape, predetermined shape, first shape, orunrestrained shape can be, for example, straight, angled, corkscrew, oroffset. The prongs or legs of one or more embodiments of the anchor,such as, for example, a staple, can be straight, curved, angled,corkscrew, or offset with respect to each other.

Anchor Delivery Tool

Turning now to FIG. 2, shown is one embodiment of an anchor 3 anddelivery instrument 6 according to one or more aspects of the invention.A guide body 4 has a cylindrical grip or hand hold and first proximaland second distal end. The body 4 can be partially or fully hollow andcontain a guide way chamber 5 for holding and orienting an anchor orstaple 3 terminating in an opening at the distal end of the guide body.The opening can be oriented axially out of the front of the body orlaterally and side mounted. The guide way chamber 5 comprises a curvedor angled slot or passage and opens perpendicular or off angle (orbetween 0-180) with respect to the long axis of the guiding body. Theradius of curvature along the passage can be constant or variable alongthe sweep of the curve. A curved nail or staple 3 can be inserted withinthe chamber 5 via a side loading window. A pusher rod 1 is carriedwithin or by the body 4 and accesses or is in communication with theguide way chamber. The rod 1 has a first proximal end that can beconfigured with a head or striking surface for hammering and a seconddistal end for transmitting force to the end of a nail, staple, oranchor 3 within the guide way chamber 5. The distal end or anvil can becurved, beveled, or angled such that the linear force of the rod can betransmitted downward or along an arc as the staple 3 is driven outthrough the curved slot of the chamber 5. The rod 1 may be rigid or atleast partially flexible in construction.

Also shown in FIG. 2 is a depth stop support 2 which can be configuredas a snap on sleeve that fits over the body 4. In other embodiments adepth stop may simply be a projection off of the body that limitsfurther travel of the body and/or guide way chamber opening within oradjacent a tissue. The depth stop may also be adjustable to allow fordifferent implantation depths or locations. The depth stop may projectin one or more directions from the long axis of the tool. Depth stopsand other instrumentation described in U.S. Pat. No. 6,821,276, hereinincorporated by reference, may be incorporated in several embodiments.

FIG. 3 is an example of an embodiment of a staple or anchor 3 with twoprongs or legs that are barbed and beveled on the outside. When thestaple is driven into a surface such as a bone the prongs may or may notbend inward or be wedged together. This action will pinch and compressthe bone tissue between the prongs while pressing outwardly against thesidewalls of the bone facilitating a stable anchorage.

The series depicted in FIGS. 4A-E shows an embodiment of a deliverydevice 6 being loaded with an anchor 3 and the push rod applying forceto the anchor and partially driving it out of the curved guide waychamber opening or lateral opening. FIG. 4B also shows the depth stopsupport sleeve 2 with a vertical slot corresponding to the guiding bodydistal slot which is aligned with the midline of the anchor and can beused to precisely implant or drive the anchor or staple around a sutureor linear structure.

In FIG. 5, an embodiment of the depth stop support is shown as anattachable sleeve that fits on or over the distal end of the guidingbody. However, many of the features of the sleeve can be machined,welded or attached directly to the body if so desired. In addition tothe vertical slot corresponding to the guiding body distal slot andadjustable depth stop, an alignment projection 8 is shown. The alignmentprojection can form a right angle with the depth stop and have a beveledtip to ease insertion. The alignment tip can be a relatively flat andrectangular projection that in use can be rotated and rocked between tovertebrae or a hole in an anulus to distract the vertebrae. Upon partialor full distraction the tip and at least part of the guiding body can beinserted between the adjacent vertebral bodies. The depth stop can limitthe amount of insertion by catching the edge of one or both of theopposing vertebral endplates. Vertebral taxis or the resistance of theanulus and endplates to further distraction can serve to immobilize theguiding body as the anchor is hammered out. Alternatively the body canbe wedged along an inferior superior plane to drive the opening of theguide way chamber against the desired anchor site. In another embodimentone or more depth stop surfaces may contain one or more barbs, spikes,nails, fasteners, or means for engaging or immovably coupling the distalend of the body to a boney structure such as a vertebral body. In oneembodiment an upper depth stop surface may be configured to engage asuperior vertebral body and a lower depth stop surface may be configuredto engage an inferior vertebral body.

Although the push rod and hammering method described infra is apreferred method of delivery other methods and devices can be used forthis purpose. For example, compressed gas and hydraulics can be utilizedfor driving. The push rod can be configured as a piston or threaded rod(that can be rotated to expel the implant) for imparting linear force.Also, the threaded rod or piston can be flexible or have joints alongits length to accommodate a curved or flexible guiding body.

Delivery instruments and devices according to one or more embodimentscan also be used to implant other devices besides anchors and the like.For example, a prosthetic device (including, but not limited to, abarrier, mesh, patch, or collapsible implant) can be attached or coupledto an anchor according to several embodiments of the present invention,such as described in U.S. Pat. Nos. 6,425,919; 6,482,235; and 6,508,839;6,821,276, all herein incorporated by reference. In several embodiments,the prosthetic device can be loaded within or along the guiding body ofthe device. The anchor and the prosthetic device may be constructed fromidentical, similar, or different materials. The anchor and prostheticdevice may be coupled or removably or reversibly. Connections betweenthe anchor and the prosthetic device may be temporary (such asrestorable or dissolvable sutures) or permanent. Instead of a prostheticdevice that is coupled or attached to the anchor, the prosthetic devicemay also be of unitary construct or integral with the anchor.

In one embodiment, an implant such as collapsible patch is coupled tothe anchor and oriented along or within the guiding body such that asthe anchor is passed through the guide way chamber slot in a downwarddirection the patch is extruded outwardly or parallel to the long axisof the body. The patch can be held within the body which can have linearslot adjacent the curved slot of the guide way chamber or alternativelythe patch can be mounted around the guide way chamber while coupled tothe anchor within the chamber. Also, the depth stop sleeve can also beused to compress and hold the patch in place.

In a further embodiment, one or more anchors can be delivered separatelyfrom one or more implants. In one embodiment, the implant is firstdelivered and positioned and then anchored in place. In anotherembodiment, the anchor is first established in the implantation site andthen the implant is delivered and connected to the anchor.

FIGS. 6A-L depicts an implantation sequence according to variousembodiments. FIG. 6A is an axial cross section of a vertebral body,shown is a star shaped treatment zone along the vertebral endplate. Thesequence shows an anchor being implanted into a posterior portion of avertebral body along an endplate. The surface of the endplate can beaccessed through a hole in the anulus. The hole in the anulus may be anaturally-occurring defect or surgically created. Methods and devices ofthe various embodiments are not limited to a single location along avertebral body or surgical approach.

Perpendicularly Driven Anchor

Various embodiments of anchor presented herein are designed to improveupon the weaknesses in conventional bone screws and staples that arelimited by surgical access and suture or anchor attachment siteplacement. For example, in the environment of the spine, the posteriorelements of vertebral bodies forming facet joints, spinal canal, neuralforamen, and the delicate nerve tissues of the spinal cord createnumerous obstacles for surgery and diagnostic and interventionalmethods. Surgical approaches have been adapted to minimize damage tothese structures and involve tight windows usually off angle to thetarget tissue.

An example of such prior art anchor and environment is depicted in FIG.7, which shows a bone screw driven into a vertebral body from aposterior lateral approach. Here the anchor on the outside of thevertebral body is ineffective for retaining an implant within the discand remains in dangerous proximity to the spinal cord. Severalembodiments are particularly advantageous because the anchor does notpresent attachment sites originating at a proximal end in the axialorientation from which they are driven. Moreover, several embodimentsare advantageous because the anchor is adapted with an expansionmechanism that provides a “mushrooming” effect, and thus the pull-outresistance is not merely limited to the friction and forces generated bythe sidewalls of the material or tissue.

Several embodiments accommodate or exploit certain geometries oranatomical structures of the body. For example, in one embodiment, theattachment site of an anchor can be presented distally from theinsertion site in a direction perpendicular or offset from the axialorientation of insertion. In one embodiment, the anchor presents alarger surface area below or embedded within a surface, thereby offeringimproved pull-out resistance without requiring an expansion or“mushrooming” step or mechanism.

In several embodiments, one or more anchors are driven into the surfaceof a first plane and present a portion on an adjacent plane or surfaceperpendicular or angled relative the first plane. Thus, the anchor isdriven into a first surface and across an adjacent surface in the sameinstance. In one or more embodiments, at least a portion of the anchorsuch as the anchor attachment site is adapted to remain above or proudof the upper or second tissue surface or plane. With respect to thefirst surface (the front facing or lower surface into which the anchoris driven), the anchor can be driven in to a depth such that it iscountersunk, left flush, or left partially external to the frontaltissue surface or plane. The anchor can also be delivered at atrajectory or angle relative to the second or top surface such that itis driven into the first surface and downwardly or upwardly across thesecond surface.

In several embodiments, the anchor is a flat plate-like nail or bradhaving a specialized keel portion and neck portion. In other embodimentsthe anchor is flat, plate-like, curved, corrugated, round, or acombination thereof. The neck can be terminated in a head or present anattachment portion along its length. The attachment portion or site canbe comprised of a more flexible piece of fabric, wire, linkage, fastenercomponent, hook eye, loop, or plate. The neck can be an extension,ridge, midline, or the apex of the keel portion. The neck can beoriented at the distal or proximal end of the keel or anywhere along itslength. The neck can be the same length as, longer than, or shorter thanthe keel but preferably it is shorter. In one embodiment, the neck is athin rod or beam. The keel portion can have a cross-section similar to awedge, “V”, “U”, “T”, and “W”, “X”, “O” and other shapes.

Anchors according to one or more embodiments have dimensions suitable tothe implantation environment. For example, in one embodiment, the anchorhas a height of about 0.2 cm to about 5 cm and a width of about 0.2 cmto about 5 cm. Anchors can have a length or depth from 0.2 cm to about 5cm. In some embodiments, the length, width, height or depth can be lessthan 0.2 cm or greater than 5 cm. In one embodiment, the anchor has alength of about 1 cm and a width of about 0.5 cm. In yet anotherembodiment, the anchor has a length of about 0.5 cm and a width of about0.25 cm. In another embodiment, the anchor is dimensioned as follows:about 0.3 cm wide, 1 cm long and 0.5 cm deep.

The length of the anchor can define a straight or curved line defined bya radius of curvature of about 0-90 degrees (e.g., about 15, 30, 45, 60,or 90 degrees). The keel, legs, extensions, blades, or fins can have aleading edge that is sharpened, left dull, or serrated. Other featuresof the neck and keel or extensions include, but are not limited to,barbs, tabs, roughened surface geometry, polished surface, coatingsseeded carrier or drug eluting coatings or elements, concavities,scalloped ridges, grooves, “feet”, ridges, voids, slots, and ingrowthopenings are shown in the attached drawings. Secondary edges or ribs canprotrude along portions of the keel to provide enhanced engagement withtissue. The neck or keel(s) can be hollow or tubular to accept tissueincorporation, cement, adhesive, therapeutic agents or another implantincluding a screw or pin. Portions of the keel or neck can further beexpanded after implantation and/or portions of the neck or keel can bedeflected or deployed as barbs after the anchor is initially implanted.

In addition to the neck and anchor attachment site, the anchor can alsoinclude an alignment means, engagement means or guide. Variations of theanchor alignment means can function to orient the anchor to a driver andcouple it thereto. The anchor alignment means can comprise alignmentcomponents such as a protrusion, recess, or fastener component mated toa portion of a delivery instrument. The anchor engagement means cancomprise engagement components or portions such as spikes, teeth,prongs, barbs, friction zones, or a combination thereof. The guide cancomprise a protrusion, slot, arrow, tab, or a combination thereof. Thus,in some embodiments, the anchor comprises means to align, means toengage, means to guide, or a combination thereof.

Turning to the drawings, FIG. 8 shows an embodiment of an anchor 25 witha leading edge 12, suture attachment sites 11, ingrowth features orvoids 13, first and second plate-like legs or lateral extensions 15, 15′defining the keel, arcuate central ridge or apex 10, centering oralignment projection 16, and feet or ridges 14, 14′. Both the wedge-likeshape of the keel portion of the implant i.e., the legs and the ridgesor flange like extensions at the end of the legs function to hold theimplant within a given tissue and to resist rotation and pull out from avariety of angles. The voids and ingrowth features serve to providesecondary stabilization over time and/or to allow chemical transfer orcellular respiration across the implantation site.

In a “V” shaped anchor or similar embodiment shown, the neck portion isbifurcated into two legs, extensions, blades, fins, or keels that meetat an apex and form an angle between about 10 and about 170 degrees. Inone embodiment, the angle is about 30-90 degrees. The apex at the pointof bifurcation can define a flat ridge or vertical extension or neckthat can contain one or more anchor attachment sites. In a “U” shapedembodiment the neck can be in the form of an arc or eye projecting alongthe length of the body of the anchor. “V” or “U” shaped anchors can bemodified to “L” shaped anchors in some embodiments.

In FIG. 9, an anchor similar to the one depicted in the previous figureis shown. The apex 10, which would correspond to the neck in otherembodiments, does not extend and instead presents a smooth curve whichcan present a less injurious profile to the anatomy in certainapplications. Also shown are ridges 70 and scalloped teeth-like surfacefeatures 71.

FIG. 10 shows another embodiment of an anchor with deployed barbs 80 and80′ These features can be held compressed within a sleeve on a deliveryinstrument or simply forced to compress inwardly as the implant isdriven in to tissue. One or more slots or recesses 82 are adapted forholding the barbs during implantation to streamline the anchors profile.

One or more barbs can exert continuous outward pressure on the sidewallsof a tissue or expand to form a shelf or flange if the tissue geometrywidens, expand or become more pliant. For example, in a vertebral bodythe implant might be driven into cortical bone and then further intocancellous bone. Upon reaching the cancellous bone, the barbs flexibleplate-like structure or engagement means, can expand or extend outwards.In another example the anchor is driven at least partially into thehollow of a boney structure such that the barbs expand and engage theinner wall of the bone. Element 81 can be arranged as an opposing barbor expansion means however one or more barbs 80, 81 can be orientedrelative to each other from 0-360 degrees. For example, the barbs orother barb-like components may be orientated relative to each other atthe following angles: 15, 30, 45, 60, 90, 120, 150, 180, or 360 degrees.

FIG. 11 shows a delivery tool with a shaft 96 with distal end 95 havingan anvil or striking surface 94 defining a leading edge mated to atleast a portion of the cross section of the trailing edge of the anchor.The shaft may be connected at its proximal end to a handle or terminatein a striking surface. Because a contour and size of the anvil surfaceis similar to those of the anchor in some embodiments, both the anchorand at least part of the distal end of the delivery tool can be driveninto a bone thereby counter sinking the anchor. Alternatively, anchorsaccording to one or more aspects of the invention can be left flush orpartially countersunk. A mounting member 90 may extend beyond theimplant when the implant is mounted or loaded on the tool. The mountingmember 90 includes a flattened lower surface 93 and a rounded bluntfront surface 91 for positioning along a bone surface, such as the topof a vertebral endplate, and a slot or engagement means 92 for acceptingand aligning an anchor.

FIG. 12 shows the anchor 25 mounted on the mounting member 90. Theextended lower surface 93 and the leading edge of the implant 12 and 12′forms a means to engage bone or other tissue. In one embodiment, thetissue (e.g., bone) engagement means comprises a device having an angledsurface that may be used to hook onto, engage, or align the instrumentwith the edge of a vertebral body or the intersection of two tissueplanes. In one embodiment, the engagement means can be used to align theimplant with the top of a vertebral endplate and its front outersurface, the anchor is then driven into and across the endplate.

FIG. 13 shows a cross-section of a vertebral body 24 having an anulusfibrosus 23 bounding nucleus pulposus 22 with an anchor 25 embedded intoa posterior aspect of an endplate and within or proximal to an anulotomyor defective region of the anulus fibrosus 23. This implantation site isalso in the vicinity of the cortical rim or ring of dense bone of thevertebral endplate. The anchor is shown countersunk into the bone alongthe P-A axis but partially proud along the inferior-superior axis (thedotted lines indicating the portion of the implant below bone surface orlevel.

FIG. 14A is an expanded view of FIG. 13 and shows dotted lines torepresent the keel portion of the anchor 25 beneath the endplatesurface. FIG. 14B is a dorsal view of FIG. 14A showing anchor 25.

In FIG. 15, a sagittal view of an implanted anchor 25 is shown at leastpartially within the defect 33 and inferior vertebral body 32. Superiorvertebral body 31 is also shown. The cross-section of the vertebralbodies depicts the denser and thicker cortical bone at the edge or rimwhere the anchor is implanted and the less dense cancellous bone withinthe vertebral body.

FIG. 16 depicts a method of delivery for one embodiment of the anchorand associated delivery tool. Shown is a top cross sectional view of avertebral body 24 and a delivery instrument 96 and an anchor 25. Thedelivery instrument or driver is used to transmit the force of a hammeror other means to drive the anchor in place. The driver can comprise aslot, holder, magnet, pins, mateable surfaces, fastener or other meansat its distal end to engage or couple with the anchor. The anchor canalso be attached to the distal end of the driver and then released oncethe desired delivery depth has been attained. Other features of a driver(not shown in FIG. 16) can include a depth stop, bone engagement meanssuch as a spiked, hooked, or angled protrusion, and/or a retractablesleeve to protect adjacent anatomy as the anchor is positioned. FIG. 16also shows a flat proximal end 1602 for hammering, if needed and aknurled handle 1600.

FIG. 17 illustrates a top cross-sectional view of an anulus repairimplant 52 lying along the inner surface of the posterior anulus thatcan be coupled, attached, or sutured to an anchor 25. The connectionbetween the anchor and implant can be permanent or detachable. Theimplant 52 can be delivered and positioned prior to, at the same timeas, or subsequent to the implantation of the anchor 25. FIGS. 18A-18Cshow various features of anchors.

In FIG. 18A, the surface level of a bone such as a vertebral endplate isshown as a dotted line. A side view is depicted. Here the leading edgeof the keel or leg portion of the implant is thinner than the trailingedge. Accordingly, in other embodiments of anchors at least a portion ofthe leading edge, profile, proximal edge or side of an implant can havea thinner or tapered profile than an opposing end, distal end, ortrailing edge or profile. FIG. 18B shows a series of anchor variationsfrom a side view in which the top portion, apex, neck, or implantattachment site 170, 171, 172, 173, 174 is symmetrical, rounded, wedgeshaped, oriented at the distal or proximal end of the anchor. FIG. 18Cshows another side view along the bone surface level depicting andanchors with features discussed infra such as a serrated leading edge,voids or ingrowth holes, and a recess for engaging a delivery tool.

FIG. 19 shows various embodiments of the anchor cross-sections 180-200including several keel profiles from a front view resistant to pulloutand offering various surface areas. Some are solid shapes as in anchorprofiles 182, 184, 187, and 200 and others are hollow and have an openmidsection as in anchor profiles 183, 185, 188.

Turning to FIG. 20, a perspective view of an anchor is shown withleading edges 12, 12′, alignment means 16, suture or fastener attachment11 site, neck 10, and voids 13. In this embodiment, the apex does notrun the entire length or depth of the anchor corresponding to the keelor opposing leg portions 15, 15′ of the anchor. Also, the neck isoriented towards the proximal end of the anchor forming a cut-out alongthe top portion of the anchor. The neck 10 is shown perpendicular to thekeel 15 but can be alternatively oriented in a range from 0-180 degreesrelative to it. In one embodiment, the neck is oriented at an angle ofabout 15, 30, 45, 60, 75, 90, 120, 150, or 180 degrees relative to thekeel

In FIG. 21, a “V” shaped anchor is shown. An “eye” or loop 11 isintegral to a neck extension portion 10 that bifurcates into two legs15, 15′. Because the leading edges 12, 12′ and at least a portion of theneck 10 is sharpened, this anchor can be driven more flush to the upperor first surface of a bone such as a vertebral endplate. Here both theneck 10 and the leg portions 15, 15′ of the device function as a keel.This embodiment also shows ridges 12 and scalloped recesses 170. Anchorsaccording to other embodiments described herein may also comprise ridgesand/or scalloped recesses.

In FIG. 22A, another embodiment of an anchor is shown. Here, three legs12, 12′, and 12″ defining the keel are provided. A relatively tallerneck 10 is provided beneath a perpendicular suture attachment member 11.The neck 10 is set back distally from the leading edge of the keelportion. FIG. 22B shows the distal tip of a delivery tool. Shown areattachment pins 180, anvil or striking surface 186, depth stop 187,mounting member 185, and shaft 96 with distal end 95.

Turning to FIG. 23A, an anchor 25 is shown with an attachment site 189for a flexible bridge 808. The bridge 808 is shown in FIG. 23B and iscoupled to the neck 10 of the anchor 25 with a first and second flexibletab 193, 194 and has an attachment 11 site at the opposing end.

The series depicted in FIGS. 24A-24C shows an anulus reinforcementsystem. FIG. 24A shows an anchor similar to the ones depicted previouslywith a bifurcated keel 15, 15′, neck 10, and attachment plate 112 with afirst and second coupling member 111, 111′ or snap surface. FIG. 24B isan exploded view of a barrier, mesh, or reinforcement plate 52 adjacentan anchor 25 wherein the anchor 25 is partially inserted or mountedwithin the distal end of a delivery tool. FIG. 24C shows all threeelements connected and mounted and ready to be driven into a tissuesite.

Another embodiment of an anulus reinforcement system is shown in FIGS.25A-25C. In this embodiment, a single attachment means 111 is used thatcan function as a fulcrum or hinge site for a flexible barrier 52 membershown in FIG. 25B. Behind or distal to the attachment means 111 is asupport member 112 or plate that is an extension of the neck 10. Thisfeature, in some embodiments, inhibits the barrier 52 from foldingbackwards and may also reinforce the barrier 52. FIG. 25C shows a hoodor sleeve 120 element that can be mounted on or carried by a deliverytool or instrument as described herein. The hood 120 retains the foldedbarrier until the anchor portion is fully established within the tissuewhereupon it is retracted.

Another embodiment is shown in FIGS. 26A-26B. This embodiment shows ananchor especially adapted for use in a vertebral body and includes anupside down “V” shaped keel portion with a sharpened leading edge. Theleading edges enable the anchor to be directly driven into the bone anddo not require a pilot hole or pre-cut. One feature of this embodimentis the leading step in the sharpened edge which presents more cuttingsurface below the surface of the bone and more forward of the distalattachment site. Alternatively, the leading edge can have multiple stepsor be curved and rounded. This profile reduces the risk that the leadingedge might pierce or damage the endplate (which is not flat but has a“dip” or cupped portion in the middle). This feature facilitatesinsertion of a longer, stronger anchor into a disc that would otherwise(because of a pronounced dip) be difficult to position at the properheight and depth into the bone without damaging the endplate.

The following example illustrates one embodiment and is not intended inany way to limit the invention. Moreover, although the following exampledescribes an anchor used in a spinal application, the anchors describedherein can be used throughout the animal body and have generalapplicability to fastener art. Such anchors can be used to join oranchor like or disparate materials or tissues together, maintainalignment of materials, reinforce a fracture within a material, andprovide an attachment site along or within a materials surface.

The anchor illustrated in FIG. 26 is used by way of example. The anchoris in the form of an upside down “Y” defined by a neck portionterminating at one end into two plate-like rectangular legs forming akeel and terminating into an suture attachment site 11 in the form of aloop on the other end. The leading edge of the legs 12 and neck 10 aresharpened and the upper portion of the legs is recessed, profiled orformed with a relief 113. The relief profile 113 can correspond to ananatomical structure. In this embodiment the forward recess or relief112 corresponds to the concavity or cupping of an endplate. The anglebetween the keel plates is around 90 degrees. The neck 10 is about 0.1millimeter high and about 0.2 wide millimeters wide and extends about0.2 millimeters. The neck 10 and attachment site 11, an “eye” or loop inthis embodiment, are mounted at the trailing or aft portion of the keel15.

The entire structure is made of nickel titanium and is machined from barstock. To be delivered, the anchor is mounted on the distal end of adriver. The driver has a striking surface on one end and an anvil on theopposing end. The anvil has the identical cross-section as the trailingedge of the anchor and extends about 0.2 cm to allow for countersinking.The anchor is coupled to the anvil by a forked protrusion that holds theneck and a pin that fits into the eye.

In one application, the anchor is used to secure an anulus repair devicerelative to a defect in the disc. A posterior-lateral approach is usedto obtain access to the damaged disc. Part of the posterior elements onthe opposing vertebral bodies may have to be removed in order to reachthe disc. The anulus repair device is then implanted through the defectand along the inner surface of the anulus.

Next the anchor, which is mounted on the distal end of the driver, isaimed at the top edge or endplate of the inferior intervertebral body.An alignment projection forming a right angle at the tip of the drive isused to align the bottom portion of the attachment loop of the anchorwith the upper surface of the endplate and to center the anchor withinthe defect. The anchor is then driven forward into the bone with lighthammering applied to the driver. The anchor is driven roughlyperpendicular to the outer surface of the vertebral body and roughlyparallel to the endplate.

The depth of insertion is controlled by the 0.2 cm countersinking anviland the depth dimension of the anchor, in this case 0.5 cm for a totaldepth of 0.7 cm which is still shy of the border of the cortical rim andthe cupping of the endplate. Only the upper portion of the loop remainsproud of the endplate surface and the annular repair device can then beconnected to it with a suture.

Graft Containment

FIG. 27A illustrates a lateral view of a stabilizer assembly 250 securedto patient tissue via a first and second fastener 252 a and 252 b. Thestabilizer or spinal fixation assembly can comprise the embodimentsdisclosed in for example U.S. Pat. Nos. 6,562,040, 6,364,880 5,437,669and 5,262,911, all herein incorporated by reference. The first fastener252 a is, in one embodiment, attached to or engaged with a superiorvertebral body 31. The second fastener 252 b is attached to or engagedwith an inferior vertebral body 32. In this embodiment, the stabilizerassembly 250 is arranged towards the posterior of the superior andinferior vertebral bodies 31, 32. Also shown is anchor device 25 thatfunctions as an anterior buttress or graft containment device.

In FIG. 27A, an anchor 25 is implanted in an upper anterior region ofthe inferior vertebral body 32. A portion of the anchor 25 extends aboveor is proud of an upper surface of the inferior vertebral body 32. Inone embodiment, the portion of the anchor 25 extending above the surfaceof the inferior vertebral body 32 is arranged to block or secure agraft, frame, plate, and/or barrier 35. In this embodiment, the anchoris implanted in the anterior portion of the endplate. In otherembodiments, the anchor may be implanted in the posterior portion.Additionally more than one anchor or anchor type as disclosed herein maybe used in more than one location to block the implant. In oneembodiment, the graft 35 comprises a femoral allograft. A wide varietyof other grafts and devices, such as loose bone grafts and/or cages canalso be secured, contained, or blocked by the anchor 25.

FIG. 27B illustrates another embodiment where an anchor 25 is attachedto a lower posterior portion of a superior vertebral body 31. Inaddition to the curvilinear anchor depicted in the illustration, otheranchors disclosed herein and included in various figures may be used forthe same purpose. For example, plate-shaped or screw anchor may be used.In one embodiment, a portion of the anchor 25 is proud of the surface ofthe superior vertebral body 31 and is further arranged to block orsecure a nonfusion intervertebral device 52. The device 52 can comprisean artificial disc or partial nucleus replacement device or other typeof implant suitable for the needs of a particular implementation.

FIGS. 28A-28F illustrate a plurality of approaches of an implantationtool 6 having one or more alignment structures 7 configured to align andlocate an anchor or other implant. FIG. 28A illustrates one embodimentof a posterior lateral approach where an anchor or other implant can bedriven into the posterior rim of either adjacent spinal end plate orproximal tissue.

FIG. 28B illustrates an embodiment of a posterior approach betweenadjacent end plates and advance of the implantation tool 6 such that adistal end of the implantation tool 6 is advanced to an anterior aspectof the respective vertebral body. FIG. 28B illustrates that an anchor orother implant can be delivered to the vertebral end plate along itsanterior cortical rim or tissue proximal thereto. In some embodiments,multiple anchors or other implants can be delivered along similarapproaches to anchor or block native tissues and/or intervertebraldevices such as one or more grafts, fusion devices, cages, anulusaugmentations, nucleus augmentation devices, and the like.

FIG. 28C illustrates an embodiment of an anterior approach for deliveryof an anchor or other implant at an anterior delivery location. FIG. 28Dillustrates a transpsoas approach for delivery of one or more anchors orother implants at a proximal delivery location. FIG. 28E illustrates anembodiment of a transforaminal approach of an implantation tool 6 forproximal delivery of one or more anchors or other implants.

FIG. 28F illustrates multiple approaches of an implantation tool 6 fordelivery of a plurality of anchors or other implants at respectivedelivery sites. FIGS. 28A-28F illustrate some of a wide variety ofembodiments and appropriate approach vectors and delivery sites can bereadily determined by the clinician based on the particular needs of thepatient. In one embodiment, a multitude of anchor devices are implantedabout at least a portion of the periphery of a vertebral endplateforming an elevated rim or artificial uncus. In another embodiment, theanchors are placed apart and connected together with one or more of aband, mesh, tube, plate, or suture.

FIGS. 29A-29F provide lateral or side views of various embodiments ofone or multiple anchors 25 arranged to block and/or provide anattachment/securing site for grafts 35 and/or implants 52. In FIGS.29A-29F, the left and right portions of each Figure correspondsgenerally to the outer rim or edges of superior and inferior vertebralbodies 31, 32. In addition to the curvilinear anchors depicted in theillustrations, other anchors disclosed herein and included in thefigures such as plate and keel type anchors may be employed andimplanted in a like manner as disclosed in FIGS. 29A-29F. Multipleanchors may be delivered about the periphery of the endplate or uncus topartially reconstruct damaged bone and/or tissue. Anchors may beconnected with one or more membranes and/or frames as described herein.

FIG. 29A illustrates a single anchor 25 implanted through a lower endplate adjacent a defect in the anulus fibrosus 23 proximal the corticalrim but extending inwardly into the inferior vertebral body 32. In thisembodiment, the anchor 25 is configured to block a nonfusionintervertebral device 52 from exiting the disc space to the left of theFigure while the remaining intact anulus is blocking the device fromextruding from the right side of the Figure.

FIG. 29B illustrates an anchor 25 blocking a fusion device or graft 35.In this embodiment, the anchor 25 is arranged to rest proximal to thegraft 35 but does not touch the graft 35.

FIG. 29C illustrates an embodiment where an anchor 25 is secured to aninferior vertebral body 32 such that the anchor 25 is barely proud thesurface of the inferior vertebral body 32. The portion of the anchor 25proud of the surface is connected to an intervertebral device 35 thatcan be either a fusion or nonfusion device as illustrated and describedinfra.

FIGS. 29D-29F illustrate a plurality of embodiments employing multipleanchors 25 where each anchor 25 can be substantially identical to otheranchors 25 or where different versions or configurations of anchors 25,25′ can be employed. FIGS. 29A-29F are simply illustrative of certainembodiments and a variety of configurations and placements can beadapted to the needs of a particular patient. Though the anchorsdepicted in FIGS. 27-30 are depicted as curvilinear anchors it should beunderstood that this is for illustrative purposes only and any anchordescribed herein may alternatively or additionally be used according tothe methods described.

In FIG. 29F, two opposing vertebral bodies 31, 32 are shown. Along theperiphery of the opposing endplates are implanted a series of anchoredimplants. Implants are used to augment (e.g., build up) or replaceweakened, damaged or missing hard or soft tissue, such as bone oranulus. In some embodiments, the anchored implants extend the uncus orcortical rim of the endplates. In certain embodiments, the anchoredimplants further comprise a membrane and optionally a frame. Theanchored implants comprise a head, neck or engagement surface to attachor engage an adjacent anchored implant or another device (e.g., abarrier, band, or graft). Multiple anchored implants can beinterconnected or stacked to form a fence, augmented or raised surface(e.g., above the endplate) to reduce or prevent the escape of extrusionof a graft or other material (artificial or natural) from the enclosedarea. In one embodiment, graft containment can be achieved effectivelyby using a series of interconnected anchored implants, thus augmentingthe uncus and reconstructing the endplate. Opposing endplates can bereconstructed in this manner. In one embodiment, both the inferior andsuperior endplates are reconstructed.

FIG. 30A illustrates a top view of an embodiment of a reconfigurablesupport member 60. The support member 60 is configured to block, providesupport or serve as a barrier to inhibit herniation of tissue ormigration of a graft or implant. In one embodiment, the support member60 comprises a plurality of generally rigid elongate members 62connected via interposed flexible connections 64. The flexibleconnections 64 are formed of a biocompatible resilient material to allowthe support member 60 to resiliently move between a first and a secondconfiguration. In some embodiments, the support member 60 canreconfigure itself automatically under resilient force provided by thesupport member 60 itself. In some embodiments, the support member 60 canbe reconfigured under tension or compression force applied to thesupport member 60. In some embodiments, the elongate members 62 andflexible connections 64 are formed of the same or similar materials. Theflexible connections 64 can comprise weakened regions of the supportmember 60 and/or regions where material comprising the support member 60is thinner and/or narrower than the material in the regions of theelongate members 62.

In some embodiments, the support member 60 comprises a connectionportion 66 configured to engage with an anchor 25 as illustrated inFIGS. 30B and 30C. In some embodiments, the connection portion 66engages with a corresponding anchor 25 via a friction fit. In someembodiments, the support member 60 can connect to a respective anchor 25via suturing, one or more fasteners, biocompatible adhesives, ultrasonicwelding, snap fit, or a variety of other methods, materials, and/orprocesses for joining separate elements. In some embodiments, thesupport member 60 and anchor 25 can be formed as an integral unit andneed not comprise separate interconnected components.

FIG. 31A illustrates a further embodiment of a support member 60 with acorresponding anchor partially engaged with a connection region 66 ofthe support member 60. FIG. 31A also illustrates that the support member60 defines a transverse dimension indicated by the designator T and alongitudinal dimension indicated by the designator L.

FIG. 31B illustrates a perspective view of the support member 60 fullyengaged with an anchor 25. As previously noted, connections between theanchor 25 and support member 60 can comprise a wide variety ofconnection means including multiple means for connecting the supportmember 60 and anchor 25. In one non-limiting example, the anchor 25 canconnect to the support member 60 via means for connecting comprisingboth a friction fit and a detent arrangement.

FIG. 31C illustrates a top view of the support member 60 in aconfiguration having a reduced transverse dimension and an elongatedlongitudinal dimension. In one embodiment, the configuration illustratedin FIG. 31C of the support member corresponds to a relaxed configurationfor a natural configuration of the support member absent applied force.The reduced transverse dimension T of the support member 60 canfacilitate advancement of the support member 60 towards a desireimplantation location.

In one embodiment, the support member 60 comprises an attachmentstructure 68 arranged at a first or leading end of the support member60. The attachment structure 68 can provide an attachment point forapplication of force to the support member 60. For example, a tensionforce can be applied to the leading end of the support member adjacentthe attachment structure 68 to draw the leading end rearward so as toreduce the longitudinal dimension and expand the transverse dimension.

In some embodiments, FIG. 31C illustrates the support member in aconfiguration having force applied. For example, in one embodiment, asleeve 120 can be arranged about the support member 60 to maintain areduced transverse dimension T. Removal of the sleeve 120 can then allowthe support member 60 to achieve a relaxed configuration having anexpanded transverse dimension T and reduced longitudinal dimension L. Inother embodiments, the configuration illustrated in FIG. 31C can bemaintained by one or more sutures or clamps applied to opposed lateralsides of the support member 60 to maintain the reduced transversedimension T. Removal or severing of such sutures or clamps can releasethe support member 60 to a relaxed state having an expanded transversedimension T and a reduced longitudinal dimension L. This configurationis illustrated schematically in FIG. 31D with the reduced longitudinaldimension L′ and the expanded transverse dimension T′.

In certain embodiments, the anchors, implants, or other devices orsystems disclosed herein can be used to facilitate vertebral fusionprocedures by containing graft material, a cage, or other intervertebraldevices or fusion materials. Many vertebral fusion procedures involveremoving part or all of the intervertebral disc and implanting a graftand/or cage to occupy the space between the vertebral bodies, therebypromoting fusion and bone growth between the adjacent vertebral bodiesto form a solid, unitary, inflexible construct in place of the damagedjoint or disc tissue. Currently available fusion procedures may alsoinvolve the use of rods, plates and screws that may be affixed to thevertebral bodies themselves and their boney posterior elements (such aspedicles, foramen, processes, and facets) to connect two or morevertebral bodies and to provide stabilization. The fusion procedures mayfurther involve graft containment devices that are affixed to the outersurface of one or more of the vertebral bodies to prevent migration orextrusion of the graft and/or cage. Currently available graftcontainment devices may utilize a plate and one or more screws. In use,a plate-like structure is placed against an outer surface of a vertebralbody such that at least a portion of the plate extends beyond the edgedefined by the intersection of the lateral surface of the vertebral bodyand the endplate (such that the plate is mounted parallel to the lateralouter surface, or periphery, of the vertebral body and perpendicular tothe endplate) and then one or more screws are inserted in the lowerportion of the plate (e.g., not extending above or beyond the endplate)and inserted within the vertebral body. Normally, a pilot hole orself-tapping screw is required to prevent damage to the bone. Both theplate and the screw by limitation of their design remain proud, above,or superficial to the outer surface (e.g., lateral surface) of thevertebral body.

In one embodiment, a method of graft containment involves the use of agraft containment device operable to reside at least flush with respectto an outer surface of a vertebral body such that no portion of thegraft containment device extends beyond the area bounded by thevertebral body or adjacent vertebral bodies. This approach minimizes thedamage to delicate tissue such as ligaments, vasculature, andneurological tissue. Graft containment devices may comprise any anchor,implant, or other device as described herein capable of presenting arecessed profile. For example, a graft containment device may comprisean anchor and an engagement/containment member or support structure,such as the support implant 350 or the implant 800 described herein. Theengagement member can be designed to connect to a graft, implant, orcage within the disc space or to merely contact the graft, implant, orcage. In some embodiments, the engagement member can press against thegraft, implant, or cage.

The engagement member can be sized relative to an access hole betweenadjacent or opposing vertebral bodies to block the hole. The engagementmember may be roughly the same size, larger, or expandable. In someembodiments, the access hole can be surgically created within an anulusof the intervertebral disc between adjacent vertebral bodies. In certainembodiments, a minimal portion or no portion of the intervertebral discis removed. The engagement member can be expandable and/or operable toprovide continuous pressure against a tissue surface, implant, cage, orgraft when it is anchored or connected to an anchor embedded within avertebral body.

In use, the graft containment devices can be implanted at any locationabout the periphery of either of the opposing endplates (e.g., at anylocation around the outer surface of the adjacent vertebral bodies). Thegraft containment devices may be implanted in opposing positions (e.g.,one within an anterior surface of one of the adjacent vertebral bodiesand one within a posterior surface of one of the adjacent vertebralbodies) to prevent migration of the graft in more than one direction.Graft containment devices can also be attached to the graft or cage toprevent migration.

In one embodiment, a graft containment device is implanted in avertebral body surface such that it is flush or countersunk within thevertebral body surface and then graft material, nucleus augmentation, ora cage is inserted through a pre-existing or surgically-created accesshole into the intervertebral disc space. A second opposing graftcontainment device can then be implanted within an opposing vertebralbody surface such that it is flush or countersunk relative to theopposing vertebral body surface.

An alternative method of graft containment involves the following steps:creating an access hole within an intervertebral disc, accessing andpreparing the space within the disc and opposing endplates, selecting avolume of graft material, implanting the graft within the disc space,selecting an engagement member or barrier operable to block the accesshole, inserting the engagement member at least partially beyond theouter aspect of the access hole such that no portion of the engagementmember is beyond the area bounded by the adjacent vertebral bodies,implanting an anchor within one of the adjacent vertebral bodies suchthat no portion of the anchor is beyond the area bounded by the adjacentvertebral body within which the anchor is implanted; and connecting theengagement member to the anchor. In certain embodiments, the method ofgraft containment is performed without expansion of the anchor (e.g.,without mushrooming or deployment of barbs). For example, no portion ofthe anchor extends outside of the boundaries created by entry into thevertebral body.

In one embodiment, the anchor and the engagement member arepre-connected prior to the procedure and inserted simultaneously. Inanother embodiment, the engagement member contacts the graft, cage orimplant. In another embodiment, the engagement member is used to impact,or displace, the graft, implant, or cage. Embodiments described hereinwith respect to graft containment may also be used for impactiongrafting or graft impaction, as further described below.

Opposing Gates

FIG. 32 illustrates a side view of a support assembly 300 configured tosupport or retain patient tissue and/or a further implant member. In oneembodiment, the support assembly 300 comprises a first anchor 25 and anopposed second anchor 25′. A first gate member 302 is connected orattached to the first anchor 25 and a second gate member 302′ issimilarly connected or attached to the corresponding second anchor 25′.In some embodiments, the gate members 302, 302′ are formed of flexiblematerial. Polymers may be used. Nitinol may also be used. In someembodiments, the gate members 302, 302′ are formed of a resilient orelastic material. In some embodiments, the gate members 302, 302′ can beat least partially rigid and movably attached to the respective anchor25, 25′ under resilient pre-loading for biased movement in a desireddirection. Such embodiments provide the ability for opposed gate member302, 302′ to resiliently engage with each other to thereby provide anobstruction or resilient support inhibiting passage of patient tissue,fluids, and/or implanted materials from passing the support assembly300.

FIG. 33 illustrates a side view of a support assembly 300 in animplanted location. In this embodiment, a first anchor 25 is secured toa lower region of a superior vertebral body 31. A second anchor 25′ issecured to an upper surface of an inferior vertebral body 32. Opposedfirst and second gate members 302, 302′ resiliently engage with eachother and are connected or attached to the respective anchors 25, 25′.In this embodiment, the gate members 302, 302′ comprise a resilient andflexible biocompatible material. As illustrated in FIG. 33, the firstand second gate members 302, 302′ can flex to accommodate patientmovement and variable loading resulting therefrom while maintaining aseal or blocking function facilitated by the resilient flexibleengagement of the opposed gate members 302, 302′. For example, in anembodiment where the support assembly 300 is implanted to resistherniation of nucleus pulposus 22, the support assembly 300 via theresilient engagement of the opposed gate members 302, 302′ can resistsuch herniation while accommodating relative movement of opposed endplates. A further advantage to certain embodiments of the supportassembly 300 is that the moveable ability of the gate members 302, 302′inhibit passage of patient tissue, fluids and/or implanted materials yetallow the inflow of nutrients, tissue fluids and the like by providing aduckbill or reed valve configuration.

In some embodiments (including, but not limited to, FIG. 33), one ormore gate members 302 can be substantially rigid and moveably attachedto a respective anchor 25. A connection or coupling between asubstantially rigid gate member 302 and a corresponding anchor 25 cancomprise a flexible connection, a pivoting connection, and/or a hingedconnection. A connection between a gate member 302 and respective anchorcan further comprise a resilient or spring aspect such that the gatemember 302 is urged in a particular direction of movement. In someembodiments, a support assembly 300 can comprise an integral assemblyand need not comprise separate connected gate member 302 and anchor 25components.

In one embodiment, (including, but not limited to, FIG. 33), a method ofclosing a defect between opposing vertebral endplates is provided. Inseveral embodiments, a duckbill-type device is used. In one embodiment,the method comprises attaching a first gate member to a superiorendplate and attaching a second gate member to an inferior endplate.Both gates have a proximal and distal end. The proximal end of the firstgate is coupled to the superior endplate. The distal end of the firstgate extends medially into an intervertebral disc space. The proximalend of the second gate is coupled to the inferior endplate. The distalend of the second gate extends medially into the intervertebral discspace. The method further comprises contacting the distal ends of thefirst and second gates to close a defect between opposing endplates. Thedistal end may touch or may be adjacent to one another. In oneembodiment, the gates are partially or wholly positioned along anendplate beyond a defective region of the anulus. In another embodiment,the gates are partially or wholly positioned in the defect. In oneembodiment, the anchor portion is in the defect and the gates are infront of the defect. A method that uses the gate system to close orbarricade a defect in which the system is placed beyond the defect isadvantageous in one embodiment because it reduces or prevents theextrusion or expulsion of nuclear material through the defect (which maybe a weakened area vulnerable to additional damage). In one embodiment,the gates are about 2-4 mm wide, about 3-6 mm long, and about 0.5-2 mmthick.

FIGS. 34A-34C illustrate additional embodiments of a support assembly300 and various embodiments of implantation location. For example, FIG.34A illustrates a support assembly 300 with a first anchor 25 attachedgenerally at a lower anterior region of a superior vertebral body 31 anda second anchor 25′ attached at an upper anterior corner of a inferiorvertebral body 32. FIG. 34A illustrates an embodiment of the supportassembly 300 implanted in a defect located generally at an anteriorposition and opposite intact anulus tissue 23. FIG. 34B illustratesanother embodiment of support assembly 300 where the anchors 25 areconfigured generally as threaded or screw shaped structures. In thisembodiment, the anchors 25 are positioned generally at an anterior outersurface of superior and inferior vertebral bodies 31, 32. In thisembodiment, the opposed gate members 302 further extend from aninterstitial region between the vertebral bodies 31, 32 outwards towardsthe respective anterior surfaces of the vertebral bodies 31, 32 forconnection with the respective anchors 25. FIG. 34C illustrates afurther embodiment where the support assembly 300 is implanted atopposed inner surfaces of a superior and inferior vertebral body 31, 32along the endplates and within or beyond the anulus. The supportassembly 300 may arranged at a posterior, anterior, or lateral positionof the vertebral bodies 31, 32.

FIGS. 35A and 35B illustrate further embodiments of a support assembly300 and various embodiments of anchor 25 configurations. FIG. 35Aillustrates that the anchors 25 comprise a generally spiked or barbedplate profile configured to be driven into and attached to respectivevertebral bodies 31, 32. FIG. 35A further illustrates that the opposedanchors 25 are presented to the patient tissue in a generally verticalanti-parallel approach. FIG. 35B illustrates an embodiment where theanchors 25 comprise a generally T-shaped or keel profile. FIG. 35Bfurther illustrates an embodiment wherein the opposed anchors 25 arepresented to the respective vertebral bodies 31, 32 in a generallyparallel transverse approach.

FIGS. 36A-36C illustrate top views of embodiments of support assembly300 and respective implantation locations with respect to patienttissue, such as an anulus 23. FIG. 36A illustrates that an anchor 25 canbe implanted in a defect region 33 such that the anchor 25 is interposedbetween an inner surface 26 and an outer surface 27 of the anulus 23.FIG. 36B illustrates an embodiment where the anchor 25 is implantedsubstantially adjacent or flush with an outer surface 27 of the anulus23. FIG. 36C illustrates an embodiment where the anchor 25 is implantedsubstantially adjacent with an inner surface 26 of the anulus 23.

FIG. 37 illustrates a further embodiment of support assembly 300comprising a plurality of interleaved leaves or fingers 304. In someembodiments, the individual leaves or fingers 304 are generally alignedwith other leaves or fingers 304 and in other embodiments the multipleleaves or fingers 304 are not generally aligned with each other.

FIGS. 38A and 38B illustrate top and side views respectively of variousconfigurations of gate member 302. As illustrated, a gate member 302 candefine a generally non-square rectangular, a generally square, atriangular, a semi-circular, a circular, or an irregular profile. Insome embodiments, a gate member 302 comprises a plurality of leaves orfingers 304 arranged to extend in divergent directions so as to describea brush-like configuration. In some embodiments, a gate member 302 cancomprise a plurality of leaves or fingers 304 extending generallyparallel to each other so as to define a finger-like profile. Othershapes and profiles of gate member 302 are possible. FIG. 38Billustrates that gate members 302 can define a generally straightprofile, an upwardly curved, a downwardly curved, a serpentine orundulating curve, an upward angled bend, a downward angled bend, angledbends of approximately zero to ninety degrees, angled bends ofapproximately 90 degrees, angled bends of approximately ninety to onehundred eighty degrees, concave, convex, and/or multifaceted profiles.

FIG. 39A illustrates an embodiment of support assembly 300 comprisingopposed gate members 302, 302′ each having a plurality of interleavedleaves or fingers 304. In this embodiment, the individual leaves orfingers 304 of each gate member 302 extend along different paths as seenin side view or are not generally aligned with each other. FIG. 39Billustrates an embodiment of support assembly 300 having opposed gatemembers 302, 302′ each having a plurality of individual leaves orfingers 304. In this embodiment, the individual leaves or fingers 304 ofeach gate member 302 are generally aligned with each other as seen inside view.

FIG. 38C illustrates further embodiments of gate members 302 including aconcave multifaceted three dimensional profile, a concave generallysmooth monotonic profile, and a profile combining both generally smoothcurved portions and generally flat or flange contours.

FIGS. 40A and 40B illustrate embodiments of support assemblies 300comprising opposed gate members 302 having a concave profile. In oneembodiment as illustrated in FIG. 40A, opposed gate members 302, 302′are substantially mirror images of each other having similar shapes,sizes and contours. The opposed gate members 302, 302′ are furtheraligned so as to engage with each other to form a substantiallycontinuous occlusion or seal aspect of the support assembly 300. FIG.40B illustrates another embodiment where the opposed gate members 302,302′ are similar in shape and contour, however can have different sizes.In the embodiment illustrated in FIG. 40B, the opposed gate members 302,302′ are configured and arranged to engage with each other in a nestedconfiguration.

FIG. 41 illustrates a further embodiment of support assembly that can besimilar to any previously described embodiment of support assembly 300.In the embodiment illustrated in FIG. 41, a connector 306 is provided toclamp, connect or provide a pivotal axis between the opposed gatemembers 302. The connector 306 can be provided in alternative or incombination with a resilient or self-engaging aspect of the gate members302 to provide additional resistance to separation of the opposed gatemembers 302. The embodiment illustrated in FIG. 41 can be preferred inimplementations where the sealing or blocking function provided by thesupport assembly 300 is preferably provided in a bi-directional manner.

Threaded Keel Anchor

FIGS. 42A and 42B illustrate in side and end views respectivelyembodiments of a first anchor structure 310 and a second anchorstructure 312. The first and second anchor structures 310, 312 can besecured or connected to each other, for example via a fastener 314. Thefirst anchor structure comprises a first threaded profile 316 configuredto allow the first anchor structure 310 to threadably engage withpatient tissue in a well known manner. The first anchor structure 310further comprises a second threaded profile configured to threadablyengage with the fastener 314.

The second anchor structure 312 comprises an attachment structure 322that can be configured as an attachment point for sutures and/or forconnection to a separate implant (not illustrated). The second anchorstructure 312 also comprises a foot or keel structure 324. The foot orkeel structure 324 is configured to secure and align the second anchorstructure 312 for connection with the first anchor structure 310. Thefoot or keel portion 324 can be further configured to engage withpatient tissue to secure the second anchor structure 312 thereto.

FIGS. 43A-43D illustrate embodiments of an implantation and attachmentprocess for the first and second anchor structures 310, 312. Asillustrated in FIG. 43A, a pilot hole can be formed in patient tissue,for example comprising an anulus. As shown in FIG. 43B, the first anchorstructure 310 can be threadably inserted into the pilot hole via acombination of rotational and/or translational forces. As illustrated inFIG. 43C, the second anchor structure 312 can then be laterally driveninto the patient tissue and into engagement with the first anchorstructure 310, for example into the second threaded profile 320. FIG.43D illustrates in end view that the fastener 314 can be threadablyengaged with the second threaded profile 320 of the first anchorstructure 310 to secure and connect the second anchor structure 312 inposition.

FIGS. 44A and 44B illustrates another embodiment of a first anchorstructure 330 and a second anchor structure 332. The first anchorstructure 330 comprises a first engagement surface 334 configured andsized to engage with a cooperating second engagement surface 336 of thesecond anchor structure 332. The first anchor structure may be a screw.The second anchor structure may be a keel terminating in a collar orother such engagement surface. The second anchor structure may have avoid or hole that facilitates coupling to an implant (e.g., a barrier).

FIGS. 45A-45C illustrate embodiments of introduction processes forsecuring the first and second anchor structures 330, 332 to each otherand to patient tissue. As illustrated in FIG. 45A, an opening or pilothole 342 can be formed in patient tissue (e.g., vertebral body) 340.FIG. 45B illustrates that the second anchor structure 332 is introducedinto the desired location in the patient tissue 340 via a generallylinear translational introduction. However, it should be noted that theopening 342 need not be formed prior to introduction of the secondanchor structure 332. For example, the second anchor structure 332 canbe introduced to the patient tissue 340 before formation of the opening342. Formation of the opening 342 is optional and may be omitted. Forexample, depending on the relative size of the first anchor structure330 and the characteristics of the patient tissue 340, the first anchorstructure 330 can comprise a self-drilling aspect reducing oreliminating the need to form the opening 342. In certain embodiments,the tissue anchors disclosed herein can be adapted to be “press fit” orimplanted without the need for a pilot hole or similar site preparatorymeasures. The tissue anchors can be at least partially countersunk topermit tissue growth behind a trailing end of the anchor to preventmigration or back-out. The cross section of the tissue anchors can bereduced in order to decrease the likelihood of bone necrosis andfracture and to maximize stability. FIG. 45C illustrates a furtherprocess wherein the first anchor structure 330 is threaded into thepatient tissue 340 and further so as to engage the first and secondengagement surfaces 334, 336. Thus, the second anchor structure 332 issecured and positioned both by its contact with the patient tissue 340and via connection with the first anchor structure 330 which is alsoengaged with the patient tissue 340.

FIGS. 46A and 46B illustrate in perspective and side views respectivelyembodiments of a support implant 350 configured for closing, blocking,reinforcing, and/or repairing defects, openings, or weakened areas in avariety of patient tissues. In some embodiments, the support implant 350is particularly adapted for use in the intervertebral disc region, suchas for reinforcing a weakened anulus and/or for closing defects. Thesupport implant can inhibit herniation of disc material or augmentationimplants outside the anulus or into defects in the anulus. Embodimentsof the support implant 350 provide these benefits while limitinginterference with spinal joint movement including flexion, extension,and lateral bending movement.

The support implant 350 comprises an anchor 25 that can be formedaccording to any of the previously described embodiments of anchor 25.In one embodiment, the anchor 25 describes a generally T-shaped profilehaving two keel portions extending generally at right angles to eachother. The anchor 25 can include solid features, roughness features,leading edges, or any other combination of features and profiles asdescribed herein.

The support implant 350 further comprises a support structure 352. Thesupport structure 352 can comprise one or more of meshes, grafts,patches, gates, membranes, stents, plugs, frames, and the like, suitablefor augmenting, fortifying, bulking, closing, blocking, occluding,and/or delivering one or more therapeutic and diagnostic agents toweakened or damaged tissues. The support structure 352 can beexpandable, can be concave or convex along one or multiple axes,oversized with respect to a defect region, correspond generally to thesize of the defect region, or be sized to cover all or a portion of aregion of intact tissue.

FIGS. 47A and 47B illustrate an anterior-posterior view and a lateralview respectively of embodiments of support implant 350. FIGS. 47A and47B are further presented as radiographic images, for example as may beobtained via radiographic imaging of the support implant 350 in animplanted location. As seen in FIGS. 47A and 47B, the support implant350 comprises a first marker 354 a and a second marker 354 b. Themarkers 354 a, 354 b can comprise iridium, platinum, platinum-iridiumalloys, or other materials configured to provide an enhanced in vivoimage, for example as may be obtained with radiographic imaging. It willbe appreciated that some embodiments of the support structure 352 cancomprise biocompatible materials which can be difficult to image in theimplantation environment. The markers 354 provide an enhanced ability toimage the support implant 350 and thereby determine the location andorientation of components of the support implant 350 that may beotherwise difficult to determine.

FIG. 48 and Detail A thereof provide a schematic side view illustrationof embodiments of a support implant 350 comprising a moveable supportstructure 352. In one embodiment, the support implant 350 comprises amoveable joint 356 between the support structure 352 and an anchor 25.In some embodiments, the moveable joint 356 defines a pivotable orhinged connection between the support structure 352 and the anchor 25.In one embodiment, the support implant 350 further defines first andsecond stop structures 360 a and 360 b configured to limit the range ofmotion of the support structure 352. In some embodiments, the supportstructure 352 is resiliently biased for movement in a desired direction.

FIG. 49 illustrates an embodiment of a delivery tool 370 configured tohold and deliver embodiments of support implants 350. Structure andoperation of the delivery tool 370 will be described in greater detailwith respect to FIGS. 50A-50E and 51 which illustrate a deploymentsequence employing the support implant 350 and delivery tool 370.

As shown in FIG. 50A, a distal end of the delivery tool 370 comprisesfirst guide structure 372. The first guide structure 372 is configuredto engage with corresponding guide structures 362 of the support implant350. The first guide structure 372 can be configured as one or more ofpins, posts, slots, grooves, dovetails, or other structures configuredto maintain an alignment and orientation between the delivery tool 370and the support implant 350. In some embodiments, the first guidestructure 372 engages with guide structures 362 formed in the anchor 25.

The delivery tool 370 further comprises second guide structures 374. Thesecond guide structures 374 are configured to engage with the supportstructure 352 and maintain the support structure 352 at a desiredorientation and position with respect to the anchor 25. For example,FIG. 50B illustrates the support implant 350 engaged with both the firstand second guide structures 372 and 374.

FIGS. 50C, 50D, and 50E illustrate a progression of the support implant350 engaging with the delivery tool 370. An end plate guide of thedelivery tool 370 advances towards the support implant 350 and urges thesecond guide structures 374 to induce the support structure 352 intoadjacency with the anchor 25. The adjacency of the support structure 352to the anchor 25 provides a reduced cross-sectional profile, for exampleas illustrated in FIG. 50E, to facilitate introduction of the supportimplant 350 to the desired implant location.

FIG. 51 illustrates the support implant 350 and engaged delivery tool370 at an implant location. In this embodiment, the implant locationcomprises a corner of patient tissue 340, such as a vertebral body 31,32. The support implant 350 and delivery tool 370 define in oneembodiment a pair of adjacent first and second locating surfaces 380,382. The first and second locating surfaces 380, 382 can be positionedto contact the patient tissue 340 to inhibit further movement of thesupport implant 350 or delivery tool 370 in multiple dimensions.

As illustrated in FIGS. 52A and 52B, force can be applied, for exampleat a driving surface 384 of the delivery tool 370 to urge the anchor 25of the support implant 350 into anchoring tissue. The delivery tool 370can then be withdrawn thereby releasing engagement between the firstguide structure 372 and the anchor 25 and the second guide structure 374and the support structure 352. The support structure 352 is thenreleased to expand or move into a desired deployed location.

FIGS. 52C-52F illustrate a variety of embodiments of deploymentpositions for the support implant 350. FIG. 52C illustrates that theanchor 25 is driven to extend substantially within cortical bone 40 butalso to extend along an interface between the cortical bone 40 andadjacent cancellous bone 41. FIG. 52C further illustrates that themoveable support structure 352 extends to obstruct or occlude a defect33 in the anulus 23. Movement of the moveable support structure 352 canbe inhibited by one or more stop structures 360 as previously describedand/or via interference with adjacent patient tissue, for example asuperior vertebral body 31. Support structure 352 can extend proximallyfrom the anchor 25 at roughly perpendicular to the endplate in which theanchor 25 is implanted and then extend distally at an angle roughlyparallel to the opposing endplate.

FIG. 52D illustrates an embodiment where the anchor 25 is driven intoposition to anchor in both cortical bone 40 and cancellous bone 41. FIG.52E illustrates an embodiment where the anchor 25 is driven to securesubstantially solely to cortical bone 40 with little to no contact withcancellous bone 41. FIG. 52E further illustrates the anchor 25 deployedat a more medial location as compared to the more posterior locations ofanchor 25 illustrated in FIGS. 52C and 52D. FIG. 52F illustrates thepositioning of the anchor 25 such that the anchor 25 resides at leastpartially within the defect 33, contacts the anulus 23 and contacts avertebral endplate of the vertebral body within which the anchor 25 hasbeen driven. The support structure 352 is positioned to occlude or blockthe defect 33, for example, to contain graft material, soft tissuematerial, and/or other material or devices.

With reference to the curvilinear anchors and delivery devices depictedinter alia in FIGS. 2-4, FIGS. 53A-53C illustrate an embodiment of adelivery tool 400 adapted to drive one or more anchors into a desiredimplantation or anchor location in patient tissue (patient tissue notillustrated). FIGS. 53A-53C also illustrate embodiments of a deploymentsequence employing the delivery tool 400 and anchor 25.

As illustrated in FIG. 53A, the delivery tool 400 comprises an urgingmember 402. The urging member 402 is configured to apply a translationalforce to the anchor 25. The urging member 402 can provide force to theanchor 25 arising from impact force, hydraulic pressure, pneumaticpressure, electromagnetic force, threaded motion, and the like.

The urging member 402 defines an engagement profile 404 at a distal ordriving end of the urging member 402. The engagement profile 404 cancomprise one or more beveled or curved profiles configured to engagewith cooperating engagement profile 28 of the anchor 25.

FIG. 53A illustrates an initial or first contact position between theurging member 402 and the anchor 25 and respective engagement profiles404, 28. As illustrated in FIG. 53A, the anchor 25 initially translatessubstantially along a longitudinal axis L upon initial contact withpatient tissue. However, contact between the beveled or curvedengagement profiles 404, 28 and curvature of the anchor 25 result in acamming action inducing the anchor 25 to rotate or curve towards atransverse axis T during the progressive introduction of the anchor 25into patient tissue. In the views provided in FIGS. 53A-53C, the anchor25 rotates by approximately ninety degrees in a clockwise direction. Asshown in FIG. 53C, during final stages of introduction of the anchor 25into patient tissue, the anchor 25 expands substantially along thetransverse axis T with significantly reduced relative motion along thelongitudinal axis L of movement of the urging member 402.

FIGS. 53A-53C further illustrate a progressive camming or slidingmovement between the opposed engagement profiles 404 and 28. Theparticular profiles or contours illustrated in FIGS. 53A-53C are simplyillustrative of one example and a variety of curves and profiles can beprovided in various embodiments of the delivery tool 400 and anchor 25depending on the needs of a particular application and thecharacteristics of the target patient tissue.

FIGS. 54A-54C illustrate another embodiment of a delivery tool 500 andsequence of operation of the delivery tool 500 in advancing an anchor 25into a desired location in target tissue 522. The delivery tool 500comprises a guide body 502. The guide body 502 is configured to providea user a grasping surface for manipulating and holding the delivery tool500. The delivery tool 500 further comprises an urging member 504 totransmit force from the delivery tool 500 to one or more anchors 25.

The delivery tool 500 further comprises a drive member 506. The drivemember 506 is attached via a hinged connection 510 to the guide body502. The hinged connection 510 can comprise one or more of a pivot, pin,axle, hinge, bearings, bushings, and the like. The hinged connection 510provides pivoting or hinged movement between the drive member 506 andthe guide body 502.

The delivery tool 500 further comprises a first cam surface 512 arrangedgenerally at a forward surface of the drive member 506. The first camsurface 512 engages with a cooperating second cam surface 514 providedat a proximal end of the urging member 504. The first and second camsurfaces 512, 514 cooperate such that hinged or pivoting movement of thedrive member 506 induces a sliding relative motion between the first andsecond cam surfaces 512, 514 to urge or advance the urging member 504outwards. In various embodiments, one or both of the first and secondcam surfaces 512, 514 can include substantially flat surfaces and curvedsurfaces. The curved surfaces can describe varying radii of curvaturealong different portions of the first and/or second cam surfaces 512,514.

The delivery tool 500 also comprises a depth stop 520 that in someembodiments is adjustable in position or location. As illustrated inFIG. 54B, the depth stop 520 provides a blocking or locating functionwith respect to the target tissue 522 inhibiting undesired relativemotion between the delivery tool 500 and the target tissue 522.

FIG. 54B further illustrates a generally transversely oriented forceapplied to the drive member 506 indicated by the designator F₁ and arrowdirected generally inwardly towards the delivery tool 500 along asubstantially transverse axis T where the delivery tool 500 extendssubstantially along a longitudinal axis L. In use, a user would hold thedelivery tool 500 in a desired position, for example by grasping theguide body 502. As the user holds the delivery tool 500 in the desiredlocation, the generally transversely directed force F₁ applied to thedrive member 506 is coupled to the distal end of the delivery tool 500to a second generally transverse force F₂ directed towards the targettissue 522. In this embodiment, the delivery tool 500 acts as a thirdclass lever to transmit force applied to the drive member F₁ as asimilarly directed force F₂ at the distal end of the delivery tool 500.

As previously noted, in some embodiments, for example as illustrated anddescribed with respect to FIGS. 53A-53C, an anchor 25 can curve orrotate during an introduction procedure to transition from a generallylongitudinal approach through a transition into a substantiallytransverse approach. As the anchor 25 begins and continues transversemotion into the target tissue 522, a reaction or recoil force F₃ isgenerated tending to drive the distal end of the delivery tool 500 andthe attached anchor 25 away from the target tissue 522. As the force F₂at the distal end of the delivery tool 500 is opposite to the reactionor recoil force F₃, these forces will tend to counteract each otherhelping to maintain the distal end of the delivery tool 500 at thedesired location and facilitating more accurate and easier introductionof the anchor 25 into the target tissue 522.

As previously noted, engagement profiles 404 and 28 can be provided onthe distal end of the urging member 504 and the anchor 25 respectivelyto facilitate the transition of advancement of the anchor 25 fromgenerally longitudinal motion transitioning to generally transversemotion. The contour and relative position of the engagement profiles 404and 28 can be adapted for more efficient transmission of forceparticularly through the transition from generally longitudinal togenerally transverse movement while maintaining the delivery tool 500 insubstantially the same position and orientation.

FIG. 54C illustrates an embodiment of the delivery tool 500 and engagedanchor 25 at a generally terminal step in an advancement procedure ofthe anchor 25. It can be seen that the anchor 25 in this embodimentextends substantially in a transverse direction. FIG. 54C illustratesfurther advantages of the delivery tool 500 in providing a self-limitingfunction. The engagement between the drive member 506 and the guide body502 via the hinged connection can be configured such that motion of thedrive member 506 is limited with respect to the guide body 502. Thedimensions and contours of the urging member 504 and drive member 506and the first and second cam surfaces 512 and 514 can preferably beselected such that the inward movement limit of the drive member 506corresponds to a desired limit of advancement of the anchor 25 withrespect to the distal end of the delivery tool 500. This provides theadvantage of automatically limiting the extent of protrusion of theurging member 504 and can provide more repeatable advancement of theanchor 25 to a desired implantation depth and along a desiredintroduction path.

FIG. 55A illustrates an embodiment of anchor 600 comprising a neck/keelportion 610 and a screw portion 620 that is implanted along the axis ofan anulotomy and disc access, just below or above the disc space into anadjacent vertebral body. The neck/keel portion 610 can be independentlyrotatable so as to extend from the screw portion 620 toward the discspace, providing an anchoring platform and site 611 from which to attachsutures, graft containment devices, and/or other medical devices. Thescrew portion 620 has an outer or major diameter that includes thethreads. The base of the threads defines an inner diameter or minordiameter that forms an axle or rod to support the threads. In FIG. 55Bthe anchor 600 is illustrated including the distal tip 613 of the screwportion 620 which can be drill-tipped (for self drilling anchors), orblunt or cone shaped for anchors that are pre-drilled in a previous stepin the procedure.

In various embodiments one or more lateral projections in the form ofneck, keel, fin, or plate can be mounted along the length of a screw orproximal to either end thereof. The attachment of the keel 610 to thescrew portion 620 may provide for substantially free and independentrotation of the screw portion 620 without imparting a significantrotational force upon the keel 610. Alternatively the keel 610 can beconnected or attached to the screw portion 620 such that it is inhibitedfrom rotation before and/or after the screw portion 620 has beenimplanted.

In one or more of the embodiments the keel 610 can be aligned in adesired direction such as vertically, e.g. extending away from thevertebral endplate and into the disc space. The keel 610 can be attachedto the screw portion 620 in a number of ways. FIGS. 56A-C illustratevarious views of a screw and keel anchor assembly 600. In FIG. 56A, thekeel 610 forms a ring 630 at two locations, both with outer diametersequal to or less than the screw's minor diameter, and generallyencircling the screw's axle at a region where there are no threads and areduced axle diameter. The screw portion 620 “captures” the keel's 610ring 630 or rings and allows the screw to spin freely about the keel610.

The most proximal end of the proximal ring 630′ of the keel 610 asillustrated in FIG. 56B may also include one or more features 640 thatallow a driver to restrain rotation and align the keel 620 in thedesired direction. In the illustration this is a series of small holesin the keel ring 630 and small pins in a corresponding driver 641 (FIG.56C). FIG. 56C illustrates the anchor 600 and one embodiment of driver641 (FIG. 56D). The driver 641 also may have a shoulder (notillustrated) that rests on the bone when the bone anchor is fullyadvanced that inhibits advancing the screw 620 beyond a desired depth.

In certain other embodiments, there may be more than one neck, keel,fin, plate, or projection, joined together or independently to thescrew, in one or more directions. The keel may be bifurcated, form aring or loop and/or comprise a neck and a bridge attachment site. FIG.57A illustrates an embodiment of the anchor device 600 in which there isneck portion defining an attachment site 611 and a bifurcated keel 610and 610′. In this embodiment the keels and neck portion are mounted atthe distal tip 613 of the screw. The screw portion 620 can be concentricor offset off axis about which the one or more keels extend. FIG. 57B issubstantially similar to the embodiment illustrated in FIG. 57A exceptthat the attachment site 611 and keels 610, 610′ are mounted at theproximal end of the screw portion 620 of the anchor 600.

FIG. 57C illustrates embodiments of implants similar to the implantillustrated in FIG. 57A in an implanted orientation within anintervertebral disc. In this case the implant was delivered from ananterior surgical approach and the keel 610 and attachment site 611 ofthe implant are situated at the posterior lateral portion of theendplate. Turning to FIG. 57D, an implant similar to the implantillustrated in FIG. 57B is provided and has been delivered via aposterior lateral surgical approach.

Further embodiments can include the addition of features to control thealignment and depth of an anchor, in relation to the surgical access anddesired final implantation location of either the keel, the screw, orboth. Besides the use of stops for depth control, an indicator and/orthe use of X-ray imaging to visualize screw depth, an alignment pinoriented along the end of the keel parallel to the axis of the screw canfacilitate visual or physical alignment of the screw and keel toward thedesired location. Various lengths of screws and length and depth ofkeels, relative to the countersunk bony surface, can provide a range ofoptions in terms of patient anatomy to properly place the strongest andmost convenient anchor and neck keel platform.

In other embodiments, the keel itself need not extend perpendicular fromthe screw's longitudinal axis, but can be jogged to one or more sides ofthe screw, and/or angled toward or away from the distal end of the screwas needed to accommodate target anatomy. In some embodiments, the keelor lateral projection can be mounted or coupled at or along a medialportion of the screw, at a distal end, at a proximal end, or anywhereelse along its length.

Various embodiments of a keel/screw anchor device described herein canalso be adapted to resist back-out or unscrewing or other undesiredmovement after implantation by the addition of a locking or engagingfeature. For example, once implanted to a desired depth with the bone,the keel, fin, plate, and/or projection locks or engages the screw. Inthis position, the screw is inhibited from rotating because the torqueand/or translation force acting on the keel is resisted by the shearforce of the bone.

Delivery methods described herein may alternatively or in additioninclude the delivery of bone cement or any suitable adhesive within,though, or adjacent the implant. The step of delivering bone cement suchas polymethylmetacrylate (PMM) can also be used to fill in the area leftby a countersunk anchor to aid to prevent further fracture, back-out ofthe screw or keel and to aid in healing if the cement is admixed withprophylactic antibiotics other agents.

In some embodiments, anchors can be driven at trajectories other thanparallel to an endplate ranging from 1-360 and preferably 10-80 degrees.FIG. 58A illustrates an embodiment wherein a screw and keel type anchor600 is implanted in an inferior endplate at about 45 degrees relative tothe endplate. In FIG. 58B two anchors 700, 700′ with a neck and keel areimplanted in the inferior and superior endplates of a vertebral body. Inthis embodiment, the anchors 700, 700′ are implanted at angles ofapproximately 10-25 degrees.

The anchors depicted in FIGS. 58A-B (and the other anchors throughoutthe disclosure) can be implanted flush to the vertebral body or endplateor countersunk. In other embodiments, anchors are driven at or proximalto the intersection or edge of a vertebral body endplate and vertebralbody outer surface.

FIGS. 59A-D illustrate an embodiment involving a locking or back-outfeature for an anchor. FIG. 59A is a side view of an anchor having aplate-like lower keel 710 and a neck 720 extending generallyperpendicularly therefrom. The neck 720 and keel 710 can furthercomprise various features described infra. Along the neck 720 isarranged an arm or extension 725 that is rotatably or flexibly engagedto the neck and terminates in one or more barb, hook, or angledprojection 726. In other embodiments, the extension 725 is a separatefloating member that slides along the neck 720. In use, as illustratedschematically in FIG. 58B, the arm 725 is raised as the neck 720 andkeel 710 are driven across and into a bone surface. When the desiredimplantation side is reached, the arm 726 can be driven downward bystriking it along its longitudinal axis and/or released from a flexedraised position such that it rotates downward to engage and at leastpartially penetrates the bone surface, such as an endplate. The arm 725can pivot freely or be under tension to compress the bone between theplate and the arm 725. Further embodiments of this locking featureinclude arm 725 that extends beyond the plate as illustrated in FIG. 59Cand a plate 710 with voids or a “U” shaped tip 728 or engagement zone asdepicted in FIG. 59D that function to engage or couple the angledprojection 726 with the plate 710.

Impaction Grafting or Graft Impaction

FIGS. 60A-60D illustrate an example embodiment of an implant 800 thatcan be used to, among other things, facilitate fusion between twoadjacent vertebrae via impaction grafting. Although the methods ofimpaction grafting will be discussed in connection with the implant 800,other embodiments of implants and anchors disclosed herein can also beused. For example, and not by way of limitation, the implant 800 canincorporate the features described with respect to the support implant350. Embodiments described herein with respect to graft impaction orimpaction grafting may also be used for graft containment, as furtherdescribed above.

The term “impaction” as used herein is a broad term and is used in itsordinary sense and includes, without limitation, contact, displacement,movement, exertion of continuous pressure or force, transferral,compaction, compression, and/or the like. The term “impact” as usedherein is a broad term and is used in its ordinary sense and includes,without limitation, displace, exert pressure or force, transfer, pressagainst, compact, compress, shove, snow plow, move, and/or the like. Theterm “contain” as used herein is a broad term and is used in itsordinary sense and includes, without limitation, engage, contact,prevent, block, occlude, abut, hold, secure, retain, and/or the like.

The implant 800 includes an anchor 810 and an engagement member 820. Theanchor 810 includes a horizontal member 812 and a vertical member 814.The horizontal member 812 can be a plate-like horizontal keel having aproximal leading end 816 and a distal trailing end 818. The verticalmember 814 can be a lateral extension, or keel, extending verticallyfrom the trailing end 818 of the horizontal member 812. In certainembodiments, the vertical member 814 can be an extension, ridge,midline, or the apex of the horizontal member 812. In other embodiments(not shown), the vertical member 814 can be oriented at the proximal end816 of the vertical member 814 or anywhere else along the length of thehorizontal member 812. The vertical member 814 can be the same lengthas, longer than, or shorter than the horizontal member 812. The verticalmember 814 can include a leading edge facing the proximal end 816 of thehorizontal member 812 that extends vertically from the horizontal member812 at an angle. The angle can be between about 10 and about 180degrees.

The engagement member 820 can be integrally or removably coupled to thevertical member 814 of the anchor 810. The engagement member 820 can bepivotably or hingedly connected to the anchor 810. The implant 800 maybe of a singular or unitary construction or may consist of multiplematerials or components that are either pre-assembled or assembledin-situ. The anchor 810 can include any of the features of the anchors25 described above. The engagement member 820 can include any of thefeatures of the support structure 352 described above.

The engagement member 820 can comprise one or more of a mesh, graft,patch, barrier, gate, membrane, stent, plug, fastener, coupler, frame,and the like, suitable for impacting, displacing, augmenting,fortifying, bulking, closing, blocking, containing, coupling to,engaging with, occluding, and/or delivering one or more therapeutic anddiagnostic agents to, an intervertebral device or adjacent tissue. Theengagement member 820 can be used to impact and/or contain nativetissues and/or intervertebral devices, such as one or more grafts,fusion devices, cages, anulus augmentations, nucleus augmentationdevices, loose graft material, soft tissue, bone cement, and the like.

The anchor 810 may be entirely rigid, partially rigid and partiallyflexible, or entirely flexible. The anchor 810 may be formed from bone(e.g., allograft, autograft or xenograft), biological tissue, orsynthetic material. The synthetic material may be polymeric, metallic,ceramic, or a combination thereof. Polymers may include PEEK, PET, orother similar material. Preferred metals may include alloys of titanium,cobalt chrome, or stainless steel. The anchor 810 can comprise aluminaor zirconia ceramics. The anchor 810 may be wholly or partly resorbable.

The engagement member 820 may be entirely rigid, partially rigid andpartially flexible, or entirely flexible. The engagement member 820 canbe compressible, such as a spring or piston, and can apply a force tograft material and/or to a vertebral endplate while implanted tostimulate bone growth. The engagement member 820 may be formed from bone(e.g., allograft, autograft, xenograft), biological tissue, or syntheticmaterial. The synthetic material may be polymeric, metallic, ceramic ora combination thereof. Polymers may include PEEK, PET, PTFE, ePTFE,polypropylene or other similar material. Preferred metals may includealloys of titanium, cobalt chrome, or stainless steel. The engagementmember 820 can alternatively comprise alumina or zirconia ceramics. Theengagement member 820 may be an extension of the anchor 810 of theimplant. Alternatively, it may be a separate component attached to theanchor component at an attachment region or location of the anchor 810.

The engagement member 820 may be solid or consist of woven materials. Incertain embodiments, the engagement member 820 is constructed of asingle or multiple layers of material. A multi-layer engagement member820 may include layers that are of substantially the same constructionor may alternatively be of variable construction. Variably constructedlayers may provide varying amounts of stiffness to various loadingdirections or may provide partial or complete resorption over variableamounts of time. The various surfaces of the engagement member 820 maybe either coated or uncoated depending on the desired interaction withsurrounding tissue. For example, the surface facing the interior of theintervertebral disc space may be comprised of or coated with materialsto promote cellular growth, whereas the surface facing the exterior ofthe intervertebral disc may be uncoated or coated with or comprised of amaterial that prevents cellular growth.

In certain embodiments, the anchors disclosed herein (including theanchor 810 of the implant 800) can be adapted to resist backout ormigration under eccentric or off-axis loading of the anchor. Resistanceto backout or migration from the applied moment can be provided by aportion of the anchor embedded within bone and the transmission offorces against tissue adjacent the embedded portion of the anchor. Theresistance to backout, pullout, or migration of the anchor 810 canadvantageously be accomplished without use of a plate and screws andwithout expanding any portion of the anchor 810 within the bone (e.g.,such that a portion of the anchor expands outward from an initialcross-section of the hole or void formed in the bone during insertion ofthe anchor). The resistance to backout, pullout, or migration can beprovided by the structure of the horizontal member 812 and the verticalmember 814, which form two offset planes that are driven within thebone.

In other embodiments, the anchors described herein can be adapted toresist backout or migration under multi-directional loads. Resistance tobackout or migration can be provided by multiple, connected surfaces ofthe embedded portion of the anchor that are arranged or oriented indifferent planes.

In certain embodiments, the anchors can be adapted to present optimizedfrictional and/or ongrowth/ingrowth surfaces of embedded portions of theanchor to exploit the anticipated directions of loading and momentapplied to the anchor. In some embodiments, the anchors can be adaptedto provide optimized pressure against the implant from surrounding boneupon implantation to maximize initial stability without risk of bonefracture or pressure necrosis.

Referring to FIGS. 60A-60D, the anchor 810 can be sized and shaped so asto decrease the likelihood of bone necrosis and fracture and to maximizestability. The horizontal member 812 and the vertical member 814 maycomprise cross-sections of approximately 0.1 mm to 2 mm and preferably0.5 mm to 1 mm. The cross-section of the horizontal member 812 and/orthe vertical member 814 can be tapered to maximize stability and/orreduce pullout. As shown in FIG. 60A, the vertical member 814 can bewedge-shaped, such that the cross-sectional thickness of the verticalmember increases towards the intersection with the horizontal member812, thereby providing thicker portions deeper into the bone and thinnerportions proximate to the surface. The wedge shape can advantageouslyresult in increased resistance to vertical pull-out and result in thevertical member 814 embedding itself as it is driven into the bone. Inalternative embodiments, the vertical member 814 can have across-section similar to a “V”, “U”, “T”, “W”, “X”, “O” or other shape.

The tissue anchors and anchored implants described herein may achieveshort term stability from initial fixation to the surrounding bone andlong term stability through integration with the surrounding bone.Initial fixation may be achieved through friction interference withsurrounding bone. Long term integration with surrounding bone can beimproved by base material choice as well as by surface treatments,features or modifications that increase surface area or by coatings ofosteoinductive or osteoconductive factors, such as bone morphogeneticproteins (BMPs) or hydroxyapatite or calcium phosphate ceramics.

Examples of surface treatments, features or modifications that can beused to increase surface area include, but are not limited to, grooves,ridges, slots, holes, surface etching, grit blasting, or plasma sprayingor arc depositing of metals. In some embodiments, certain surfacemodifications decrease the fatigue and ultimate strength of the basematerial. Certain surface modifications may further require additionalmaterial and therefore thickness (for example, due to weakenedstructural integrity caused by voids in the material), which may beadverse to the desired application. In addition, certain surfacemodifications may add to production expense and/or complexity ofmanufacture. In several embodiments, methods of providing anchoredimplants comprise optimizing surface modifications of the anchoredimplants (e.g., by providing non-uniform surfaces).

With continued reference to FIGS. 60A-60D, in certain embodiments, theuse of surface treatments, features or modifications can be optimized topromote both initial and long term fixation of a tissue anchor bylimiting the application of the surface treatments, features, ormodifications to regions intended to experience the greatest loadagainst surrounding bone.

FIGS. 60A-60D illustrate modified regions 815 configured (e.g.,optimized) to initiate bone growth or fixation when the anchor 810 issubjected to eccentric/off-axis loads. The implant 800 comprises ahorizontal member 812 (in this embodiment, a keel or plate member) and avertical member 814 (in this embodiment, a keel or plate member) mountedalong its length proximal to its posterior end. The vertical member 814provides an attachment site (e.g., to attach engagement member 820)positioned such that a load (e.g., eccentric load) applied to theattachment site is transmitted to the horizontal member 812 as a moment.The vertical member 814 can advantageously operate to resist torsionalloads on the attachment site. For example, if the load (e.g., eccentricload) applied to the attachment site is in the posterior direction, themoment causes the upper surface of the horizontal member 812 anterior tothe attachment site and the lower surface of the horizontal member 812posterior to the attachment site to press against adjacent bone.

The surfaces undergoing load or pressing against the bone (e.g., themodified regions 815) can preferably be treated with bone ingrowthtreatments, surface enhancements, or provided with grooves, voids,ridges, protrusions, high frictional coefficient geometries, and thelike. Other examples of preferred surface treatments may includetechniques to create a roughened surface, such as grit blasting,chemical etching, plasma spray or arc deposit coatings with metals suchas titanium or titanium alloys. The modified surface regions 815 maypreferably be coated with biologic growth enhancements, such as calciumphosphate or hydroxyaptetite ceramics or bone morphogenetic proteins.The modified surface regions 815 may be combined with antibiotic orosteoinductive or osteoconductive or tissue-growth promoting coatings ofall or a portion of the implant 800.

In certain embodiments, the horizontal member 812 can have dual,non-uniform surfaces. As shown in FIGS. 60A-60D, the upper surface ofthe leading end 816 of the horizontal member 812 and the lower surfaceof the trailing end 818 of the horizontal member 812 are “roughened,” orotherwise modified, while the remaining portions of the upper surfaceand the lower surface are left smooth (e.g., not modified or optimized).By only treating or optimizing the surfaces that will most likely beactively engaged under eccentric or other loading, the non-“optimized”portions of the horizontal member 812 may advantageously retain theirfull strength, may be designed thinner, and/or may avoid material loss.In such a manner, the anchor 810 can be optimized while stillmaintaining structural integrity. In some embodiments, the verticalmember 814 can include surface modifications in a similar manner asdescribed with respect to the horizontal member 812. In otherembodiments, the entire outer surface, or substantially the entire outersurface, of the horizontal member 812 and/or vertical member 814 caninclude surface modifications.

In certain embodiments, the implants and anchors described herein (forexample, the implant 800) can be used to perform impaction grafting ofthe intervertebral space to facilitate interbody fusion. The impactiongrafting can be performed in conjunction with a spinal fusion surgicalprocedure in which two or more vertebrae are joined or fused together.In one embodiment, the method of impaction grafting comprises performingan interbody fusion, inserting loose bone graft material, and drivingthe implant 800 into, across, and recessed within a vertebral body andendplate of a functional spine unit, thereby impacting and securing theloose bone graft material between opposing endplates of the spine. Incertain embodiments, the implant 800 does more than contain, or preventexpulsion of, the graft material; for example, the implant 800 canprovide a constant force to compact loose bone graft material, therebystimulating bone growth and enhancing fusion between adjacent vertebralbodies.

The implants and anchors described herein can be implemented usingvarious surgical approaches. Such implants and anchors may be used inconjunction with various surgical fusion techniques, such as posteriorlumbar interbody fusion (PLIF), anterior lumbar interbody fusion (ALIF),transforaminal lumbar interbody fusion (TLIF), or extreme lateralinterbody fusion (XLIF). In PLIF techniques, the vertebrae can beaccessed through an incision (e.g., three to six inches) in thepatient's back. In ALIF techniques, the vertebrae can be accessedthrough an incision (e.g., three to five inches) in the lower abdominalarea. In TLIF techniques, the vertebrae can be accessed from the side ofthe spinal canal through a midline incision in the patient's back (e.g.,a posterior-lateral approach). The XLIF technique involves approachingthe vertebrae through a small (e.g., approximately one inch) incision onthe patient's side. In certain embodiments, the fusion techniques caninclude removing or trimming at least a portion of the functional spineunit (e.g., lamina, facet, pedicle, articular process, transverseprocess, spinous process). The various vertebral fusion techniques canbe used to fuse adjacent cervical, thoracic, and/or lumbar vertebrae.

FIGS. 61A-61F illustrate an embodiment of an example TLIF procedurefacilitated by use of the implant 800 for impaction grafting. The TLIFapproach and technique can be used, for example, to fuse two adjacentlumbar vertebrae together. In the TLIF procedure, the vertebrae arereached through an incision in the patient's back using aposterior-lateral approach. The intervertebral disc space may then beprepared. Preparation of the disc space may include removing a portionof the affected disc (e.g., a portion of the nucleus pulposus and/oranulus fibrosus). In certain embodiments, only a de minimis portion ornone of the affected disc is removed. For example, the least amount ofnucleus pulposus and anulus fibrosus material possible while stillenabling fusion between adjacent vertebral bodies can be removed. Inother embodiments, the entire nucleus, anulus, and/or disc is removed.In certain embodiments, portions of the spinal bone can be removed toallow access to or enhanced space for the nerve roots or to provideeasier access for delivery tools. Preparation of the disc space may alsoinclude preparing the bone surfaces of adjacent vertebrae for fusion.Such preparation may involve removing adjacent disc tissue, scraping orroughening surfaces of the vertebral body, or forming grooves, channels,concavities, and/or recesses in the bone to accept implants, grafts,cages, artificial tissue, and/or treatment agents. Preparation of thedisc space may also involve the application of energy such as heat,light, radiation, electricity, radio frequency (RF) waves, sonic pulses,and/or cooling.

FIG. 61A illustrates an access portal 821 formed during the preparationof the disc space. The access portal 821 can be formed at a defective orweakened portion of the anulus 823 or at any convenient location foraccess to the disc space. The access portal 821 can be a surgicallycreated hole or a naturally-occurring, pre-existing hole in the disc. Inthe illustrated embodiments, the majority of the anulus 823 has beenleft in tact. In other embodiments, the anulus 823 can be substantiallyor entirely removed. In yet other embodiments, no portion of the anulus823 is removed. The size of the access portal 821 can correspond to thedimensions of the delivery tools or the impaction implant to be insertedwithin the disc space. For example, the access portal 821 can have alateral dimension of about 3 mm to about 20 mm and a vertical dimensionof about 3 mm to about 15 mm. In other embodiments, the access portal821 can have dimensions equaling the entire posterior aspect of the disc(about 40 mm) and the maximum height of a disc under distraction (about20 mm).

Once the disc space is prepared, graft material (e.g., allograft,autograft, xenograft, synthetic material) and/or a fusion cage can beinserted to promote fusion between the vertebrae. In certainembodiments, the graft material and/or fusion cage can include bonemorphogenetic proteins. The graft material can comprise a dense graft,loose graft material, or a combination of both. FIG. 61B illustrates thedisc space after insertion of bone graft material 830 along theposterior edge of the disc. FIG. 61C illustrates the insertion of afusion cage 825 through the entry portal 821 using a delivery tool 828(e.g., medical forceps, tweezers or the like). The fusion cage 825 canbe centered within the disc space adjacent the bone graft material 830.

FIG. 61D illustrates the disc space following insertion of additionalbone graft material 830. As shown, the bone graft material 830 maycomprise loose graft material that has a tendency to leak or extrude outof the portal 821. After the graft material and/or cage have beeninserted, a bone anchor (e.g., the implant 800) is driven into the outersurface of one or both of the adjacent vertebral bodies to be fused.

FIG. 61E illustrates delivery of the implant 800 to facilitate impactionof the bone graft material 830. As the implant 800 is driven into theexterior lateral surface of the vertebral body, the engagement member820 of the implant 800 is driven along the adjacent endplate surface. Asthe engagement member 820, which may preferably comprise a plate-like orflexible member, is driven against the loose graft material 830, it iseventually driven at least partially across the disc space and impactedagainst the graft material 830 or the cage 825. This action may compactor displace the loose graft material 830 securely into place where, overtime, it will fuse the adjacent vertebrae. In certain embodiments, theengagement member 820 can be used to “snow plow”, shove, impart force,displace, compact, or otherwise transfer the loose graft material 830that is extruding from a defect in the anulus 823 into the disc space.In other embodiments, the engagement member 820 can be used to snowplow, shove, impart force, displace, compact, or otherwise transfer thegraft material 830 further within the disc space. In certainembodiments, the engagement member 820 compacts the graft material 830against the fusion cage 825.

In certain embodiments, the delivery tool 829 used for insertion of theimplant 800 is the delivery tool 370 of FIG. 49; in other embodiments,other delivery tools can be used. The anchor 810 of the implant 800 canbe driven into the bone of the vertebral body, for example, by applyingforce to the driving surface 384 of the delivery tool 370. Theengagement member 820 can serve as a barrier to prevent expulsion of thebone graft material 830 and/or as an impaction member to provide a forceto compact the bone graft material 830 to promote interbody fusion.

FIG. 61F illustrates the implant 800 in its final, fully-implantedposition. In certain embodiments, the implant 800 can be recessed orcountersunk within the bone. For example, the trailing edges of theimplant 800 can be recessed therein about 1 mm to about 10 mm, or about1 mm to about 20 mm (e.g., about 1-3 mm, 3-6 mm, 6-10 mm, 10-15 mm and15-20 mm, and overlapping ranges thereof). In certain embodiments, theimplant 800 can be positioned within the vertebral body such that nopart of the implant 800 extends or protrudes beyond an outer surface ofthe vertebral body. The recessing of the implant 800 within thevertebral body advantageously reduces the possibility that any portionof the implant 800 will contact delicate tissue such as ligaments,vasculature and/or neurological structures. The recessed area of boneposterior of the implant 800 may be treated with adhesives, cements,energy, or bone growth promoters. In other embodiments, the trailingedge of the implant 800 can be driven flush with the outer surface ofthe vertebral body or slightly proud of the outer surface of thevertebral body.

FIG. 62 illustrates a perspective view of FIG. 61F from the perspectiveof the delivery tool 828 approaching the disc from a posterior-lateralincision in the back. The implant 800 of FIG. 62 is implanted such thatthe trailing edge of the implant 800 is roughly flush with (e.g.,slightly recessed within) the outer surface of the vertebral body.Establishing the anchor 810 entirely below the endplate surfaceadvantageously provides an anchor with two offset planes beneath theendplate surface without the expansion of the anchor (e.g., without a“mushrooming” effect and without deployment of barbs after insertion forretention). In certain embodiments, the anchor 810 is implanted at leastpartially within the portal 821, or defect, within the anulus 823. Theanchor 810 may reside in a position such that it touches the anulus 823and the vertebral endplate of the vertebral body within which it isimplanted.

In other embodiments, the implant 800 can be embedded further within oralong the bone to provide greater impaction. One or more embodimentsprovide a recessable anchor operable to present a prosthetic or tissueattachment site above an adjacent bone surface. For example, as shown inFIG. 62, a portion of the vertical member 814 of the recessed anchor 810extends proud or above the endplate surface. Additional instrumentation(such as rods, screws, plates, connectors, articulating surfaces) mayalso be used at this time to further stabilize the spine according tovarious methods described herein.

In certain disc environments, the implant 800 is advantageouslyimplanted without the use of a plate, rod, or screws. For example, useof a plate or rod and screw alone for containment can result in graftmaterial or soft tissue material extruding out on either side of theplate. The plate or rod alone cannot use the anulus itself to aid inholding the graft or soft tissue material in because the plate or rod ispositioned on the outside surface of the anulus. The plate or rod alonemay be ineffective at impacting, compacting, or displacing graftmaterial or soft tissue material within the disc space because the plateor rod is positioned outside the anulus and may not penetrate into theanulus or disc space.

FIG. 63 illustrates another embodiment of a TLIF procedure supplementedby impaction of the loose graft material 830 by the implant 800. Asshown, the fusion cage 825 is inserted across the disc space until itabuts the opposing lateral anterior anulus or nucleus tissue adjacentthe anulus and then loose bone material or graft 830 is insertedadjacent the fusion cage 825. In certain embodiments, an impaction tooland/or the implant 800 is partially inserted to impact the graftmaterial 830 against the fusion cage 825 and then fully implanted withinan outer surface of the vertebral body to prevent migration of the graftmaterial 830 or the fusion cage 825. In this manner, the implant 800,the graft material 830, and the fusion cage 825 are tightly held withinthe disc space under tension and may form an integral unit over time.

FIG. 64A illustrates an embodiment of a PLIF procedure supplemented byimpaction grafting utilizing the implant 800. As shown, the accessportal 821 can be formed in a central posterior region of the anulus823. The fusion cage 825 can be positioned along the posterior border ofthe disc space. In certain embodiments, the engagement member 820 of theimplant 800 can be positioned to directly contact the fusion cage 825.The fusion cage 825 and/or the implant 800 can impact the graft material830, thereby compacting the graft material 830 to promote fusion. Thesteps of the PLIF procedure can include any of the steps described abovefor the TLIF procedure.

FIG. 64B illustrates an alternative embodiment of a PLIF procedure inwhich two access portals 821A,B are formed in the anulus 823, two fusioncages 825A,B are inserted within the disc space, and two implants 800A,Bare driven within the vertebral body. Loose bone graft material 830 canbe inserted to fill at least a portion of the remaining disc space.Various methods described herein may involve contacting or driving theengagement member 820 against the fusion cages 825 or graft material830. As shown, the engagement member 820B is brought into contact withthe fusion cage 825B and the engagement member 820A is spaced apart fromthe fusion cage 825A. Additional portals may be formed, additional cagesmay be inserted, and additional implants may be implanted in alternativeembodiments.

FIG. 65A illustrates an embodiment of impaction grafting in conjunctionwith an ALIF procedure. As shown, the ALIF procedure includes insertionof graft material 830 (solid and/or loose) and a fusion cage 825 throughan access portal in the anterior region of the disc. After insertion ofthe graft material 830 and the fusion cage 825, two implants 800A,B aredriven into adjacent vertebral bodies. In certain embodiments, theimplants 800A,B are driven entirely within cortical bone. In otherembodiments, the implants 800A,B are driven at least partially withincancellous bone. The implant 800A is driven into the superior vertebralbody and the implant 800B is driven into the inferior vertebral body.The engagement members 820 of the implants 800A,B can be used to compactthe graft material 830 to promote fusion. Any of the features of themethods, techniques, and devices described above with respect to FIGS.32-41 can also be utilized. As described above for the PLIF and ALIFprocedures, multiple implants can be used in TLIF and XLIF procedures aswell. For example, a surgeon can implant one implant using an anteriorapproach into an anterior region of a vertebral body/disc and canimplant another implant into an opposing posterior location using aposterior or posterior-lateral approach. Any combination of surgicalaccess methods can be used.

FIG. 65B illustrates an embodiment of a graft impaction and/orcontainment method and device for use in conjunction with an ALIFprocedure. The embodiment of FIG. 65B may advantageously be used to fusecervical vertebrae, but may also be used to fuse thoracic or lumbarvertebrae. In certain disc environments, it may be advantageous tocombine a graft engagement/containment member 822 with a plate 824,wherein the graft engagement/containment member 822 displaces materialfrom an anulus defect created surgically during an anterior cervicaldiscectomy and fusion. The graft engagement/containment member 822 canincorporate the features of the graft engagement member 820.

The plate 824 can be anchored to one or both surrounding vertebralbodies anywhere along the outer surface of the one or both vertebralbodies either with bone screws or anchors 826A,B that are eitherintegral to the plate 824 or applied separately. As the plate 824 issecured to the vertebral body or bodies, the graft engagement member 822impacts or displaces graft or other material from the anular defecttoward the center of the disc. In other embodiments, the plate 824 andgraft engagement member 822 can be used to resist the outward migrationof or contain intradiscal materials. In certain embodiments, a fusioncage, BMPs, and/or other materials or implants can be inserted withinthe disc space.

The graft engagement member 822 can be coupled to the plate 824 by anysuitable attachment means (such as glue or other adhesive element,mechanical coupling, or suture). In certain embodiments, the plate 824can be substituted with a rod or other like device. In otherembodiments, more than one plate or rod can be used. The plate 824 canbe made of biocompatible material (such as metal or polymeric material).The embodiment of FIG. 65B can be used in conjunction with othersurgical fusion procedures as well. For example, the plate 824 can beattached to a lateral, anterior-lateral, or posterior-lateral region ofthe vertebral body during a TLIF, PLIF, or XLIF procedure, or acombination or variation of any of the foregoing procedures.

The fusion cage 825 can be rigid or substantially rigid. The fusion cage825 can comprise a metallic, ceramic, or polymeric material. The fusioncage 825 can be substantially hollow or substantially solid. In certainembodiments, the fusion cage 825 is substantially tubular. In otherembodiments, the fusion cage 825 has a substantially rectangularcross-section. The fusion cage 825 can be straight, substantiallystraight, or curved (e.g., concave or convex). In certain embodiments,the fusion cage 825 comprises a “banana cage.” The fusion cage 825 caninclude openings at each end and a plurality of openings throughout thebody to allow passage of loose graft material therethrough.

The implants and anchors described herein (for example, the implant 800)can also be used to contain or impact soft tissue or nuclearaugmentation material, either natural or synthetic, into the disc spaceduring insertion of a containment or impaction prosthesis. The sequencesdescribed in, for example, FIGS. 61-65 could alternatively involve theimpaction of nucleus tissue, in addition to, or instead of, fusionmaterials (such as bone graft material or the like). For example, theimplants and anchors described herein can be used to perform animpaction step during implantation to compress or impact nucleuspulposus or prosthetic or transplanted nuclear augmentation material aspart of the closure or reconstruction of an anular defect during adiscectomy or nuclear augmentation procedure.

As part of this method, native nucleus or augmentation material can bemoved toward the center of the disc space during insertion of theimplant (e.g., the implant 800). As an example, nuclear material may bewithin the defective region in the anulus prior to implant insertion.The engagement member of the implant can be positioned at the exteriorof the anular defect and then impacted toward the interior of the discspace. As the engagement member is driven into the disc space, itsimultaneously displaces the nucleus from the anular defect and into thenuclear space within the disc. Such a method may be employed to increasenuclear pressure, increase disc height, increase disc space, ordecompress neurological tissue. The anular defect may be a weakenedportion of the anulus or a surgically created hole.

In various embodiments, the implants and anchors (e.g., the implant 800)may be used to contain, impact, and/or compact native or artificialnucleus and or anulus, growth stimulating or promoting agents, seeded ordrug eluting textiles or gels, cellular transplants, bone (e.g.,allograft, autograft, xenograft), or rigid, flexible, or flowableartificial materials within the disc space.

In some embodiments, implantation or delivery of the implant 800comprises a two-step process. In some embodiments, a first instrument(e.g., a delivery tool, impaction tool) can be used to drive and impactan engagement member of an implant against augmentation, graft, ornative disc material within a disc space and then a separate instrument(e.g., a fixation tool, implantation tool, or second delivery tool) canbe used to implant and anchor the engagement member to an adjacentvertebral body or to spine tissue. The engagement member and anchor canbe coupled prior to the first step or during the second step in variousembodiments.

Any of the devices or methods herein may be used to anchor or attachimplants, grafts, tendons, patches, orthodontia, sutures, etc. in avariety of orthopedic applications including the knee, shoulder, wrist,cranium, ankle, heel and jaw.

Some embodiments have been described in connection with the accompanyingdrawings. However, it should be understood that the figures are notdrawn to scale. Distances, angles, etc. are merely illustrative and donot necessarily bear an exact relationship to actual dimensions andlayout of the devices illustrated. Components can be added, removed,and/or rearranged. Additionally, the skilled artisan will recognize thatany of the above-described methods can be carried out using anyappropriate apparatus.

Conditional language, for example, among others, “can,” “could,”“might,” or “may,” unless specifically stated otherwise, or otherwiseunderstood within the context as used, is generally intended to conveythat certain embodiments include, while other embodiments do notinclude, certain features, elements and/or steps. Thus, such conditionallanguage is not generally intended to imply that features, elementsand/or steps are in any way required for one or more embodiments or thatone or more embodiments necessarily include logic for deciding, with orwithout user input or prompting, whether these features, elements and/orsteps are included or are to be performed in any particular embodiment.

Modifications can be made to the embodiments disclosed herein withoutdeparting from the spirit of the present invention. For example, methodsteps need not be performed in the order set forth herein. Further, oneor more elements of any given figure described herein can be used withother figures. The titles and headings used herein should not be used tolimit the scope of any embodiments. Features included under one headingmay be incorporated into embodiments disclosed under different headings.Therefore, it should be clearly understood that the forms of the presentinvention are illustrative only and are not intended to limit the scopeof the present invention. Further, no disclaimer of subject matter isintended and the scope of the embodiments disclosed herein should beascertained from a full and fair reading of the claims.

What is claimed is:
 1. A method of inserting and retaining interbodyfusion material within an intervertebral disc, the method comprising:inserting an anchored implant comprising a bone anchoring portion and anengagement portion to a location adjacent an intervertebral disc betweenadjacent vertebral bodies, accessing a disc space between the adjacentvertebral bodies; inserting at least one bone fusion material within thedisc space; driving said bone anchoring portion into an outer surface ofat least one of the adjacent vertebral bodies along a direction ofaccess; and recessing the bone anchoring portion within said outersurface of said at least one adjacent vertebral body such that noportion of the bone anchoring portion lies beyond said outer surface. 2.The method of claim 1, wherein the engagement portion is entirely rigid.3. The method of claim 1, wherein the engagement portion is entirelyflexible.
 4. The method of claim 1, wherein the engagement portion ispartially rigid and partially flexible.
 5. The method of claim 1,wherein accessing the disc space comprises penetrating an anulusfibrosus of the intervertebral disc and forming a hole through theanulus fibrosus.
 6. The method of claim 1, wherein driving said boneanchoring portion into an outer surface of at least one of the adjacentvertebral bodies comprises driving said bone anchoring portion into theouter surface at an angle substantially parallel to the endplatesurfaces of the adjacent vertebral bodies.
 7. The method of claim 1,wherein recessing the bone anchoring portion within said outer surfaceof said at least one adjacent vertebral body comprises recessing thebone anchoring portion such that a trailing end of the bone anchoringportion is recessed greater than 1 mm within the outer surface of saidat least one adjacent vertebral body.
 8. The method of claim 1, whereinthe at least one bone fusion material comprises a fusion cage.
 9. Themethod of claim 1, wherein the at least one bone fusion materialcomprises a fusion cage and one or more of autologous bone graft,allograft, demineralized bone matrix, collagen, and bone morphogenicmaterials.
 10. The method of claim 1, wherein the at least one bonefusion material comprises one or more of autologous bone graft,allograft, demineralized bone matrix, collagen, and bone morphogenicmaterials.
 11. The method of claim 1, wherein the engagement portion andthe bone anchoring portion form a unitary construct.
 12. The method ofclaim 1, wherein the engagement portion and the bone anchoring portionare removably coupled.